Spindle structure and electric spindle having the same

Abstract

The utility model provides a kind of main shaft structure and the electric spindle with it, wherein, main shaft structure, comprising: main body structure;Front bearing assembly, is set on main body structure;Rear bearing structure, is movably set on the end of main body structure away from front bearing assembly;Driving structure, including driving part and reinforcing part, driving part is set on main body structure and is located between front bearing assembly and rear bearing structure, driving part is driven connection with main body structure, to drive main body structure rotation;Wherein, reinforcing part is set on driving part, to carry out structural reinforcement to driving part.The utility model effectively solves the problem of poor rigidity in prior art electric spindle.

Description

Technical Field

[0001] This utility model relates to the field of machine tool technology, and more specifically, to a spindle structure and an electric spindle having the same. Background Technology

[0002] Currently, with the rapid development of CNC technology and continuous scientific progress, CNC machine tools, as the "mother machines" of the equipment manufacturing industry, have been widely used in the automotive, mold, aerospace, and military industries. Among them, the electric spindle is the core component of high-speed, high-precision CNC machine tools; it is a spindle system integrating multiple technological units. High-speed electric spindles, due to their high speed and high precision, greatly improve the machining efficiency and accuracy of machine tools. The performance of the electric spindle directly affects the machining quality of CNC machine tools. Electric spindles require both high speed and high rigidity. High speed can effectively avoid the occurrence of machining burrs, while high rigidity can, to a certain extent, prevent machining vibration.

[0003] However, due to the limitations of its size and specifications, electric spindles are prone to deformation under stress during operation, which reduces their rigidity and consequently lowers their machining efficiency and quality. Utility Model Content

[0004] The main objective of this invention is to provide a spindle structure and an electric spindle having the same, so as to solve the problem of poor rigidity of electric spindles in the prior art.

[0005] To achieve the above objectives, according to one aspect of the present invention, a spindle structure is provided, comprising: a main structure; a front bearing assembly sleeved on the main structure; a rear bearing structure movably sleeved on the end of the main structure away from the front bearing assembly; and a drive structure including a drive member and a reinforcing member, wherein the drive member is sleeved on the main structure and located between the front bearing assembly and the rear bearing structure, and the drive member is drivenly connected to the main structure to drive the main structure to rotate; wherein the reinforcing member is sleeved on the drive member to structurally reinforce the drive member.

[0006] Furthermore, the driving member has a first mating part, and the reinforcing member has a second mating part. One of the first mating part and the second mating part is a protrusion, and the other of the first mating part and the second mating part is a recess. The protrusion extends into the recess and engages with the recess.

[0007] Furthermore, there are multiple first mating parts, which are spaced apart along the circumference of the driving member; there are also multiple second mating parts, which are arranged in a one-to-one correspondence with the multiple first mating parts.

[0008] Furthermore, the main structure includes a front end, a connecting part, and a main body that are interconnected. The connecting part is located between the front end and the main body. The driving member is driven to the main body to drive the main body to rotate the front end and the connecting part. The diameter D1 of the front end, the diameter D2 of the connecting part, and the diameter D3 of the main body satisfy the following relationship: D1 < D2, D3 < D2.

[0009] Furthermore, the front bearing assembly is fitted onto the front end, and the front bearing assembly includes a first bearing structure and a second bearing structure. The second bearing structure is located on the side of the first bearing structure near the connecting part. The distance between the midpoint J3 of the drive structure and the midpoint J2 of the second bearing structure is X, the distance between the midpoint J3 and the end face of the connecting part near the front end is X1, and the distance between the midpoint J3 and the midpoint J1 of the first bearing structure is X2. Among them, X, X1, and X2 satisfy the following condition: X1 < X < X2.

[0010] Furthermore, the rear bearing structure is fitted onto the end of the main body away from the connecting part; the distance between the midpoint J3 and the midpoint J4 of the rear bearing structure is Y, the distance between the midpoint J3 and the end face of the drive structure near the rear bearing structure is Y1, and the distance between the midpoint J3 and the end face of the main body away from the connecting part is Y2; wherein, Y, Y1 and Y2 satisfy the following condition: Y1 < Y ​​< Y2.

[0011] Furthermore, the spindle structure also includes a cooling structure, which is located within the main structure. The cooling structure includes cooling channels for containing cooling medium, which is used to cool the main structure.

[0012] Furthermore, the spindle structure also includes a detection structure, which is installed on the main structure to detect the temperature of the main structure.

[0013] Furthermore, the main shaft structure also includes an alarm structure, which is connected to the detection structure to issue an alarm signal when the temperature of the main structure exceeds a temperature threshold. The alarm signal includes at least one of a light signal and a sound signal.

[0014] According to another aspect of the present invention, an electric spindle is provided, which includes the spindle structure described above.

[0015] The present invention utilizes a front bearing assembly of the spindle structure, which is fitted onto the main body structure. A rear bearing structure is movably fitted onto the end of the main body structure furthest from the front bearing assembly. The drive structure includes a drive member and a reinforcing member. The drive member is fitted onto the main body structure and located between the front bearing assembly and the rear bearing structure, and is driven by the main body structure to drive its rotation. The reinforcing member is fitted onto the drive member to structurally strengthen it. Thus, the drive structure, mounted on the main body structure, drives the main body structure through the drive member, ensuring the reliability of the main body structure's rotation. Simultaneously, the reinforcing member provides external support for the drive member. When a large external force is applied, the reinforcing member reduces the stress on the drive member and decreases its deformation, thereby enhancing the rigidity of the drive structure and the spindle structure, thus solving the problem of poor rigidity in existing electric spindles. Furthermore, the reinforcing member can buffer the impact force on the drive member, enhancing the spindle structure's rigidity while reducing vibration and ensuring the spindle's machining accuracy. Meanwhile, the arrangement of the front bearing assembly and rear bearing structure not only provides support for the main structure, ensuring its smooth rotation and reliability, but also further enhances the rigidity of the main structure, reduces vibration, and improves the machining efficiency and accuracy of the spindle structure. Furthermore, the movable rear bearing arrangement allows for long-term rotation of the main structure, ensuring the stability of the spindle structure during high-speed and long-term operation. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the overall structure of an embodiment of the spindle structure according to the present invention is shown;

[0018] Figure 2 It shows Figure 1 A three-dimensional diagram of the drive structure of the spindle structure in the image;

[0019] Figure 3 It shows Figure 2 The main view of the drive structure of the spindle structure in the middle;

[0020] Figure 4 It shows Figure 2 A top view of the drive structure of the main spindle structure.

[0021] The above figures include the following reference numerals:

[0022] 10. Main structure; 11. Front end; 12. Connecting part; 13. Main body;

[0023] 20. Front bearing assembly; 21. First bearing structure; 22. Second bearing structure;

[0024] 30. Rear bearing structure;

[0025] 40. Drive structure; 41. Drive component; 411. First mating part; 42. Reinforcing component; 421. Second mating part. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] In this utility model, unless otherwise stated, directional terms such as "upper" and "lower" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction; similarly, for ease of understanding and description, "left" and "right" are generally used in relation to the left and right shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0029] To address the problem of poor rigidity in existing electric spindles, this application provides a spindle structure and an electric spindle having the same.

[0030] like Figures 1 to 4 As shown, the spindle structure includes a main body structure 10, a front bearing assembly 20, a rear bearing structure 30, and a drive structure 40. The front bearing assembly 20 is sleeved on the main body structure 10. The rear bearing structure 30 is movably sleeved on the end of the main body structure 10 away from the front bearing assembly 20. The drive structure 40 includes a drive member 41 and a reinforcing member 42. The drive member 41 is sleeved on the main body structure 10 and located between the front bearing assembly 20 and the rear bearing structure 30. The drive member 41 is drivenly connected to the main body structure 10 to drive the main body structure 10 to rotate. The reinforcing member 42 is sleeved on the drive member 41 to structurally reinforce the drive member 41.

[0031] Applying the technical solution of this embodiment, the front bearing assembly 20 of the spindle structure is sleeved on the main body structure 10. The rear bearing structure 30 is movably sleeved on the end of the main body structure 10 away from the front bearing assembly 20. The drive structure 40 includes a drive member 41 and a reinforcing member 42. The drive member 41 is sleeved on the main body structure 10 and located between the front bearing assembly 20 and the rear bearing structure 30. The drive member 41 is driven by the main body structure 10 to drive the main body structure 10 to rotate. The reinforcing member 42 is sleeved on the drive member 41 to structurally reinforce the drive member 41. In this way, the drive structure 40, which is provided on the main body structure 10, drives the main body structure 10 through the drive member 41, ensuring the reliability of the rotation of the main body structure 10. Meanwhile, the drive structure 40, through the reinforcing member 42, provides external support for the drive member 41. When a large external force is applied, the reinforcing member 42 reduces the stress on the drive member 41 and decreases its deformation, thereby enhancing the rigidity of the drive structure 40 and improving the rigidity of the spindle structure. This solves the problem of poor rigidity in existing electric spindles. The reinforcing member 42 also buffers the impact of external forces on the drive member 41, enhancing the rigidity of the spindle structure while reducing its vibration and ensuring machining accuracy. Furthermore, the arrangement of the front bearing assembly 20 and the rear bearing structure 30 provides support for the main structure 10, ensuring its smooth rotation and reliability. It also further enhances the rigidity of the main structure 10, reduces its vibration, and improves machining efficiency and accuracy. The movable rear bearing allows for long-term rotation of the main structure 10, ensuring the stability of the spindle structure during high-speed and long-term operation.

[0032] In this embodiment, the driving component 41 is a rotor.

[0033] Specifically, the spindle structure also includes a stator. The rotor directly drives the spindle to rotate through electromagnetic interaction with the stator, which reduces energy loss and mechanical vibration during power transmission, improves the spindle's response speed and accuracy, simplifies the mechanical structure, and reduces maintenance costs.

[0034] like Figures 2 to 4As shown, the drive component 41 has a first mating portion 411, and the reinforcing component 42 has a second mating portion 421. One of the first mating portions 411 and the second mating portion 421 is a protrusion, and the other is a recess. The protrusion extends into the recess and engages with it. This engaging engagement between the first mating portion 411 and the second mating portion 421 not only achieves the connection between the drive component 41 and the reinforcing component 42, ensuring the stability of the connection, but also provides more reliable structural stability compared to simple planar or point contact. Especially under high-speed rotation or heavy load conditions, this design ensures that there is no relative displacement between the drive component 41 and the reinforcing component 42, improving the operational reliability and safety of the entire spindle structure. Simultaneously, this design reduces the installation difficulty for workers and improves their installation and maintenance efficiency. Meanwhile, the above settings can also optimize the thermal expansion management of the spindle structure, ensuring that the connection between the drive component 41 and the reinforcing component 42 remains stable and reliable under different temperature conditions, which helps to maintain the geometric accuracy and performance of the spindle structure.

[0035] In this embodiment, the first mating part 411 is a recess, and the second mating part 421 is a protrusion.

[0036] In an embodiment not shown in the accompanying drawings, the first mating part is a protrusion and the second mating part is a recess.

[0037] Specifically, along the axial direction of the drive member 41, the length of the first mating part 411 is consistent with the axial width of the drive member 41, and the axial width of the second mating part 421 is consistent with that of the reinforcing member 42, so as to increase the mating area between the first mating part 411 and the second mating part 421, thereby enhancing the connection strength between the drive member 41 and the reinforcing member 42 and improving the connection stability between the drive member 41 and the reinforcing member 42.

[0038] like Figure 2 and Figure 4 As shown, there are multiple first mating parts 411, which are spaced apart circumferentially along the drive member 41. There are also multiple second mating parts 421, which are arranged in a one-to-one correspondence with the first mating parts 411. This arrangement of multiple first mating parts 411 and multiple second mating parts 421 further enhances the connection stability between the drive member 41 and the reinforcing member 42, making the entire drive structure 40 more stable and able to withstand greater forces. Furthermore, the evenly distributed multiple first mating parts 411 and second mating parts 421 avoid localized stress concentration, prevent deformation of the drive member 41, ensure the rigidity of the drive member 41, further improve the rigidity of the spindle structure, and enhance machining accuracy and efficiency.

[0039] In this embodiment, four first mating parts 411 are provided.

[0040] It should be noted that the number of first mating parts 411 is not limited to this and can be adjusted according to working conditions and usage requirements. Optionally, the number of first mating parts 411 may be two, three, six, nine, or more.

[0041] like Figure 1 As shown, the main structure 10 includes a front end portion 11, a connecting portion 12, and a main body portion 13 connected to each other. The connecting portion 12 is located between the front end portion 11 and the main body portion 13. The driving member 41 is drivenly connected to the main body portion 13 to drive the main body portion 13 to rotate the front end portion 11 and the connecting portion 12. The diameters D1 of the front end portion 11, D2 of the connecting portion 12, and D3 of the main body portion 13 satisfy the following relationship: D1 < D2, D3 < D2. This arrangement of the front end portion 11, the main body portion 13, and the connecting portion 12 forms a stepped structure, allowing the main structure 10 to have different diameters, resulting in different coefficients of thermal expansion. This reduces the degree of thermal deformation, ensures the shape stability of the main structure 10 during high-speed rotation, and further guarantees the rigidity of the main structure 10. Simultaneously, the driving member 41 drives the main body portion 13 to drive the main structure 10, reducing torque transmission losses, improving energy conversion efficiency, and ensuring sufficient power and rapid response of the main structure 10 during high-speed operation.

[0042] like Figure 1 As shown, the front bearing assembly 20 is sleeved on the front end portion 11. The front bearing assembly 20 includes a first bearing structure 21 and a second bearing structure 22, with the second bearing structure 22 located on the side of the first bearing structure 21 near the connecting portion 12. The distance between the midpoint J3 of the drive structure 40 and the midpoint J2 of the second bearing structure 22 is X; the distance between the midpoint J3 and the end face of the connecting portion 12 near the front end portion 11 is X1; and the distance between the midpoint J3 and the midpoint J1 of the first bearing structure 21 is X2. X, X1, and X2 satisfy the condition: X1 < X < X2. This arrangement restricts the structural distribution among the first bearing structure 21, the second bearing structure 22, and the drive structure 40, effectively optimizing the load distribution of the entire spindle. This helps balance the radial and axial loads borne by the front bearing assembly 20 and the drive structure 40, reducing wear on the front bearing assembly 20 due to uneven load distribution, reducing the deformation of the drive structure 40 and the main body structure 10, and extending the service life of the spindle structure. Meanwhile, the above settings can also reduce the impact of thermal deformation on the geometry of the main structure 10, ensure the thermal stability of the spindle structure, and avoid a reduction in machining accuracy.

[0043] In this embodiment, the first bearing structure 21 includes two interconnected angular contact ball bearings, and the midpoint between the distance between the end faces of the two angular contact ball bearings that are away from each other is the midpoint J1.

[0044] In this embodiment, the second bearing structure 22 includes two interconnected angular contact ball bearings, and the midpoint of the distance between the end faces of the two angular contact ball bearings away from each other is the midpoint J2.

[0045] In this embodiment, the midpoint of the overall length of the drive structure 40 is the midpoint J3.

[0046] like Figure 1 As shown, the rear bearing structure 30 is fitted onto the end of the main body 13 away from the connecting part 12. The distance between the midpoint J3 and the midpoint J4 of the rear bearing structure 30 is Y, the distance between the midpoint J3 and the end face of the drive structure 40 near the rear bearing structure 30 is Y1, and the distance between the midpoint J3 and the end face of the main body 13 away from the connecting part 12 is Y2. Y, Y1, and Y2 satisfy the following condition: Y1 < Y ​​< Y2. This arrangement restricts the structural distribution between the drive structure 40 and the rear bearing structure 30, effectively optimizing the load distribution of the entire spindle. It helps balance the radial and axial loads borne by the rear bearing structure 30 and the drive structure 40, reducing wear on the rear bearing structure 30 caused by uneven load distribution, reducing the deformation of the drive structure 40 and the main body structure 10, and extending the service life of the spindle structure. Simultaneously, this arrangement also reduces the impact of thermal deformation on the geometry of the main body structure 10, ensuring the thermal stability of the spindle structure and preventing a decrease in machining accuracy.

[0047] In this embodiment, the rear bearing structure 30 is a cylindrical roller bearing, and the midpoint of the overall length of the cylindrical roller bearing is the midpoint J4.

[0048] Specifically, the spindle structure also includes a cooling structure, which is located within the main body structure 10. The cooling structure includes cooling channels that contain a cooling medium, which is used to cool the main body structure 10. In this way, the main body structure 10 reduces its own heat during high-speed rotation through the cooling structure, reducing component deformation and vibration caused by excessive temperature, ensuring the operational stability of the main body structure 10, extending its service life, and improving the machining reliability of the spindle structure.

[0049] In this embodiment, the cooling medium is water.

[0050] Specifically, the spindle structure also includes a detection structure, which is installed on the main body structure 10 to detect the temperature of the main body structure 10. In this way, the above-mentioned setup can monitor the temperature changes of the main body structure 10 in real time, and can promptly detect temperature abnormalities in the main body structure 10. This allows the operators to take cooling measures or adjust processing parameters in time to avoid potential damage, and also improves the automation level of the spindle structure.

[0051] Specifically, the spindle structure also includes an alarm structure connected to the detection structure. This alarm structure issues an alarm signal when the temperature of the main structure 10 exceeds a temperature threshold. The alarm signal includes at least one of a light signal and an audible signal. Thus, when the temperature of the main structure 10 exceeds the temperature threshold, the alarm structure can promptly remind operators to make corresponding adjustments, avoiding potential equipment failures or safety accidents and ensuring the operational safety and stability of the electric spindle. The inclusion of at least one light signal and audible signal makes the alarm system more versatile and effective. The light signal can be quickly noticed by operators in noisy workshop environments, while the audible signal can also serve as a reminder even when visibility is limited. This dual alarm method ensures timely delivery of warning information under various working conditions, further enhancing the operational safety and stability of the electric spindle.

[0052] In this embodiment, the detection structure can also be combined with the cooling structure to adjust the flow rate and volume of the cooling medium in the cooling channel in real time according to the temperature of the main structure 10, thereby further ensuring the operational stability and reliability of the spindle structure.

[0053] In this embodiment, the temperature threshold is 90°C.

[0054] In this embodiment, the staff performed parametric modeling of the main structure 10, using the formula Px = Fx 2 (3L-X) / 6EA, calculate the deformation at each position of the main structure 10. Where Px represents the radial deformation at position X of the main structure 10; F is the force applied to the corresponding position of the main structure 10; E is the elastic modulus of the main structure 10; and A is the cross-sectional area of ​​the corresponding position of the main structure 10.

[0055] Specifically, the overall length L of the main structure 10 satisfies: L=X+Y+Z, thus the radial deformation P2 at the midpoint J2 satisfies: P2=F(X+Y+Z). 3 (2L+X) / 6EA; The radial variable P3 at the midpoint J3 satisfies: P3=F(Y+Z) 2(3X+2Y+2Z) / 6EA. Where Z is the distance between the end face of the drive structure 40 near the rear bearing structure 30 and the end face of the main body 13 away from the front end 11. Then, the X values ​​within the range of X1 and X2, and the Y values ​​within the range of Y1 and Y2, are substituted into the formula. It is set that the static stiffness of the main body structure 10 is maximized when the radial deformation P2 at the midpoint J2 is at its minimum. Simultaneously, the radial deformation P3 at the midpoint J3 is set to be < 2μm to ensure subsequent machining accuracy. Then, the optimization design function of the AYSYS finite element analysis software is used for iterative calculation. Iteration stops when P3 > 2μm. Finally, the X and Y values ​​when P2 is minimum and P3 < 2μm are obtained. The positions of the front bearing assembly 20, drive structure 40, and rear bearing structure 30 are then installed according to the X and Y values ​​to improve the rigidity and natural frequency of the spindle structure.

[0056] This application also provides an electric spindle, which includes the spindle structure described above.

[0057] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:

[0058] The front bearing assembly of the spindle structure is fitted onto the main body structure. The rear bearing structure is movably fitted onto the end of the main body structure away from the front bearing assembly. The drive structure includes a drive component and a reinforcing component. The drive component is fitted onto the main body structure and located between the front bearing assembly and the rear bearing structure. The drive component is driven by the main body structure to drive its rotation. The reinforcing component is fitted onto the drive component to structurally strengthen it. Thus, the drive structure, mounted on the main body structure, drives the main body structure through the drive component, ensuring the reliability of the main body structure's rotation. Simultaneously, the drive structure, through the reinforcing component, provides external support for the drive component. When a large external force is applied, the reinforcing component reduces the stress on the drive component and decreases its deformation, thereby enhancing the rigidity of the drive structure and improving the rigidity of the spindle structure. This solves the problem of poor rigidity in existing electric spindles. Furthermore, the reinforcing component can buffer the impact force on the drive component, enhancing the rigidity of the spindle structure while reducing its vibration, ensuring the machining accuracy of the spindle structure. Meanwhile, the arrangement of the front bearing assembly and rear bearing structure not only provides support for the main structure, ensuring its smooth rotation and reliability, but also further enhances the rigidity of the main structure, reduces vibration, and improves the machining efficiency and accuracy of the spindle structure. Furthermore, the movable rear bearing arrangement allows for long-term rotation of the main structure, ensuring the stability of the spindle structure during high-speed and long-term operation.

[0059] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0060] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0061] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A spindle structure, characterized in that, include: Main structure (10); The front bearing assembly (20) is fitted onto the main structure (10); The rear bearing structure (30) is movably sleeved on the end of the main body structure (10) away from the front bearing assembly (20); The drive structure (40) includes a drive member (41) and a reinforcing member (42). The drive member (41) is sleeved on the main body structure (10) and located between the front bearing assembly (20) and the rear bearing structure (30). The drive member (41) is driven to the main body structure (10) to drive the main body structure (10) to rotate. The reinforcing member (42) is sleeved on the drive member (41) to structurally reinforce the drive member (41).

2. The spindle structure according to claim 1, characterized in that, The driving member (41) has a first mating part (411), and the reinforcing member (42) has a second mating part (421). One of the first mating part (411) and the second mating part (421) is a protrusion, and the other of the first mating part (411) and the second mating part (421) is a recess. The protrusion extends into the recess and engages with the recess.

3. The spindle structure according to claim 2, characterized in that, There are multiple first mating parts (411), and the multiple first mating parts (411) are arranged at intervals along the circumference of the drive member (41). There are multiple second mating parts (421), and the multiple second mating parts (421) are arranged one-to-one with the multiple first mating parts (411).

4. The spindle structure according to claim 1, characterized in that, The main structure (10) includes a front end (11), a connecting part (12), and a main body (13) that are connected to each other. The connecting part (12) is located between the front end (11) and the main body (13). The driving member (41) is driven to the main body (13) to drive the main body (13) to rotate the front end (11) and the connecting part (12). The diameters of the front end portion (11), D1, D2, and D3 of the connecting portion (12) satisfy the following relationship: D1 < D2, D3 < D2.

5. The spindle structure according to claim 4, characterized in that, The front bearing assembly (20) is sleeved on the front end (11). The front bearing assembly (20) includes a first bearing structure (21) and a second bearing structure (22). The second bearing structure (22) is located on the side of the first bearing structure (21) near the connecting part (12). The distance between the midpoint J3 of the drive structure (40) and the midpoint J2 of the second bearing structure (22) is X, the distance between the midpoint J3 and the end face of the connecting part (12) near the front end (11) is X1, and the distance between the midpoint J3 and the midpoint J1 of the first bearing structure (21) is X2; wherein, X, X1 and X2 satisfy the following condition: X1 < X < X2.

6. The spindle structure according to claim 5, characterized in that, The rear bearing structure (30) is sleeved on the end of the main body (13) away from the connecting part (12); The distance between the midpoint J3 and the midpoint J4 of the rear bearing structure (30) is Y, the distance between the midpoint J3 and the end face of the drive structure (40) near the rear bearing structure (30) is Y1, and the distance between the midpoint J3 and the end face of the main body (13) away from the connecting part (12) is Y2; wherein, Y, Y1 and Y2 satisfy the following condition: Y1 < Y ​​< Y2.

7. The spindle structure according to claim 1, characterized in that, The spindle structure also includes a cooling structure, which is disposed within the main structure (10). The cooling structure includes a cooling channel for containing a cooling medium for cooling the main structure (10).

8. The spindle structure according to claim 7, characterized in that, The spindle structure also includes a detection structure, which is disposed on the main body structure (10) to detect the temperature of the main body structure (10).

9. The spindle structure according to claim 8, characterized in that, The main shaft structure also includes an alarm structure connected to the detection structure to issue an alarm signal when the temperature of the main structure (10) exceeds a temperature threshold. The alarm signal includes at least one of a light signal and a sound signal.

10. An electric spindle, characterized in that, The electric spindle comprises the spindle structure according to any one of claims 1 to 9.

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