Spindle structure and machine tool thereof

Abstract

The utility model provides a kind of main shaft structure and lathe, main shaft structure includes: main shaft box;Main shaft, main shaft is set on main shaft box, one end of main shaft is connected with tool chuck, and main shaft center through-hole is communicated with chuck center through-hole of tool chuck;Fluid transmission component, fluid transmission component is set in the side of main shaft box away from tool chuck and is connected with main shaft, and outlet of fluid transmission component is communicated with main shaft center through-hole;First driving component, it is set on main shaft box and is driven connection with main shaft, to drive main shaft rotation, and the rotation axis of first driving component is spaced apart with the axis of main shaft, to solve the problem that lathe main shaft in prior art cannot carry out center water cooling to the contact point of tool and workpiece.

Description

Technical Field

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

[0002] In today's manufacturing industry, CNC machine tools, as high-precision and high-efficiency machining tools, are widely used in the processing of various precision parts. Among them, the spindle, as one of the core components of a CNC machine tool, directly determines the machine tool's machining capabilities and accuracy. Most spindles in current technology are direct-drive mechanical spindles, which connect the servo motor directly to the spindle via a coupling, thereby achieving efficient power transmission.

[0003] However, existing direct-drive mechanical spindles have certain limitations when deep drilling is required. The servo motor is directly connected to the spindle via a coupling. This structural design makes the motor shaft and the spindle axis coaxial, so the spindle does not have the characteristic of having through holes. The cutting fluid cannot directly reach the contact point between the tool and the workpiece through the inside of the spindle, thus it cannot provide an effective spindle center outlet cooling function. Utility Model Content

[0004] The main objective of this invention is to provide a spindle structure and machine tool thereof to solve the problem that the machine tool spindle in the prior art cannot provide central water cooling at the contact point between the tool and the workpiece.

[0005] To achieve the above objectives, according to one aspect of the present invention, a spindle structure is provided, comprising: a spindle housing; a spindle disposed on the spindle housing, one end of the spindle being connected to a tool chuck, the spindle's central through-hole communicating with the tool chuck's central through-hole; a fluid transmission component disposed on the side of the spindle housing away from the tool chuck and connected to the spindle, the fluid transmission component's outlet communicating with the spindle's central through-hole; and a first drive component disposed on the spindle housing and drivenly connected to the spindle to drive the spindle to rotate, the rotation axis of the first drive component being spaced apart from the spindle's axis.

[0006] Furthermore, the spindle structure also includes a timing belt assembly, which is disposed inside the spindle box. The driven end of the timing belt assembly is connected to the spindle. The first driving component is a drive motor, the fixed end of which is disposed on the spindle box. The output end of the drive motor is connected to the driving end of the timing belt assembly to drive the spindle to rotate through the timing belt assembly.

[0007] Furthermore, the synchronous belt assembly includes a synchronous belt, a first transmission pulley, and a second transmission pulley, wherein the output end of the drive motor is drivenly connected to the first transmission pulley, the second transmission pulley is drivenly connected to the main shaft, and the synchronous belt is sleeved on the first transmission pulley and the second transmission pulley.

[0008] Furthermore, the fluid transmission component also includes a fluid switching valve, a fluid transmission pipe, and a rotary joint. The first inlet of the fluid switching valve is used to connect to the liquid supply tank. One end of the fluid transmission pipe is connected to the outlet of the fluid switching valve, and the other end of the fluid transmission pipe is connected to the inlet of the rotary joint. The outlet of the rotary joint is connected to the central through hole of the spindle to deliver the coolant from the liquid supply tank to the central through hole of the spindle.

[0009] Furthermore, the fluid transmission pipe includes a first pipe section and a second pipe section that are perpendicular to each other and connected. The first pipe section is connected to a fluid switching valve, and the second pipe section is connected to a rotary joint to deliver coolant into the rotary joint. And / or, the fluid switching valve is also provided with a second inlet for connecting to an external gas supply component to deliver high-pressure gas from the gas supply component into the rotary joint.

[0010] Furthermore, the spindle structure also includes a tie rod, which is disposed outside the spindle box and located between the spindle and the rotary joint. The rotating part of the rotary joint is fixedly connected to the tie rod, and the tie rod is provided with a tie rod center through hole for connecting the outlet of the rotary joint with the center through hole of the spindle.

[0011] Furthermore, the spindle structure also includes a second drive component, which is mounted on the spindle box and located on the side of the spindle box away from the tool chuck. The second drive component is connected to the pull rod drive to drive the pull rod to move in the vertical direction.

[0012] Furthermore, the second drive component includes a drive cylinder, a mounting assembly, and a first connector. The two ends of the mounting assembly are respectively connected to the spindle box and the fixed end of the drive cylinder. The output end of the drive cylinder is driven to connect to the first connector. The first connector is sleeved on the outside of the rotary joint and fixedly connected to the fixed part of the rotary joint, so that under the drive of the second drive component, the spindle can be driven to move along its own axis through the rotary joint.

[0013] Furthermore, the mounting assembly includes a mounting plate and mounting brackets. The mounting plate is arranged along an axis perpendicular to the spindle. There are multiple mounting brackets, which are spaced apart between the mounting plate and the spindle box to connect the mounting plate and the spindle box. The fixed end of the drive cylinder is located on the mounting plate. The first connecting member is located within the mounting space formed by the multiple mounting brackets. And / or, the first connecting member is provided with a clearance groove for at least a portion of the fluid transmission component of the fluid transmission pipe.

[0014] According to another aspect of the present invention, a machine tool is provided, including a spindle structure, wherein the spindle structure is the spindle structure described above.

[0015] By applying the technical solution of this utility model, the spindle structure of this application is provided with a spindle box, a spindle, a fluid transmission component and a first drive component, and the fluid transmission component is located on the side of the spindle box away from the tool chuck and connected to the spindle. The outlet of the fluid transmission component is connected to the central through hole of the spindle, which effectively realizes the central transmission of cutting fluid or high-pressure gas. During machining, the coolant can directly act on the contact point between the tool and the workpiece, significantly improving the cooling effect and promoting timely chip removal. High-pressure gas can be used for cleaning and dry cutting operations during tool changes, enhancing the versatility of the spindle structure. In this application, the first drive component is connected to the spindle drive, and the rotation axis of the first drive component is spaced apart from the axis of the spindle. This avoids the spatial limitations and interference problems caused by the coaxiality of the drive motor and the spindle in the traditional direct-drive spindle structure. This layout not only provides sufficient space to install fluid transmission components, but also ensures the stability and efficiency of the spindle during rotation. It allows the spindle to achieve central coolant supply while rotating, thus providing more stable cooling conditions in complex and high-precision machining tasks, reducing the impact of thermal deformation, and improving machining accuracy and efficiency. This effectively solves the problem in the prior art that machine tool spindles cannot provide central water cooling at the contact point between the tool and the workpiece. 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 front view of an embodiment of the spindle structure according to the present invention and its machine tool is shown; and

[0018] Figure 2 It shows according to Figure 1 A magnified view of point A shown below;

[0019] Figure 3 This is a side view of an embodiment of the spindle structure according to the present invention and its machine tool.

[0020] Figure 4 It shows according to Figure 3 A magnified view of point B shown.

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

[0022] 10. Spindle box; 20. Spindle; 30. Tool chuck; 40. Connecting rod; 50. Fluid transmission component; 60. First drive component; 70. Second drive component;

[0023] 510, First inlet; 520, Fluid switching valve; 530, Fluid transfer pipe; 540, Rotary joint;

[0024] 521. Second entrance;

[0025] 531. First pipe section; 532. Second pipe section;

[0026] 610. Synchronous belt assembly; 611. Synchronous belt; 612. First transmission pulley; 613. Second transmission pulley; 620. Drive motor;

[0027] 710. Drive cylinder; 720. Mounting assembly; 730. First connecting piece;

[0028] 721. Mounting plate; 722. Mounting bracket; 723. Mounting space;

[0029] 731. Avoid the groove. Detailed Implementation

[0030] 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.

[0031] like Figures 1 to 4 As shown, the spindle structure of this application includes: a spindle housing 10; a spindle 20, which is mounted on the spindle housing 10, with one end of the spindle 20 connected to a tool chuck 30, and the spindle center through hole of the spindle 20 communicating with the chuck center through hole of the tool chuck 30; a fluid transmission component 50, which is mounted on the side of the spindle housing 10 away from the tool chuck 30 and connected to the spindle 20, with the outlet of the fluid transmission component 50 communicating with the spindle center through hole; and a first drive component 60, which is mounted on the spindle housing 10 and drivenly connected to the spindle 20 to drive the spindle 20 to rotate, with the rotation axis of the first drive component 60 spaced apart from the axis of the spindle 20.

[0032] Thus, the spindle structure of this application is provided with a spindle box 10, a spindle 20, a fluid transmission component 50 and a first drive component 60. The fluid transmission component 50 is located on the side of the spindle box 10 away from the tool chuck 30 and connected to the spindle 20. The outlet of the fluid transmission component 50 is connected to the central through hole of the spindle, which effectively realizes the central transmission of cutting fluid or high-pressure gas. During machining, the coolant can directly act on the contact point between the tool and the workpiece, significantly improving the cooling effect and promoting timely chip removal. High-pressure gas can be used for cleaning and dry cutting operations during tool changes, enhancing the versatility of the spindle structure. In this application, the first drive component 60 is driven and connected to the spindle 20, and the rotation axis of the first drive component 60 is spaced apart from the axis of the spindle 20. This avoids the spatial limitations and interference problems caused by the coaxiality of the drive motor and the spindle in the traditional direct-drive spindle structure. This layout not only provides sufficient space to install fluid transmission components, but also ensures the stability and efficiency of the spindle during rotation, allowing the spindle to achieve central coolant supply while rotating. This provides more stable cooling conditions in complex and high-precision machining tasks, reduces the impact of thermal deformation, and improves machining accuracy and efficiency. It effectively solves the problem that machine tool spindles in the prior art cannot provide central water cooling at the contact point between the tool and the workpiece.

[0033] like Figure 1 and Figure 2 As shown, the spindle structure also includes a timing belt assembly 610, which is disposed inside the spindle box 10. The driven end of the timing belt assembly 610 is connected to the spindle 20. The first drive component 60 is a drive motor 620, the fixed end of which is disposed on the spindle box 10. The output end of the drive motor 620 is connected to the driving end of the timing belt assembly 610 to drive the spindle 20 to rotate through the timing belt assembly 610.

[0034] Preferably, a synchronous belt assembly 610 is used as the power transmission mechanism between the spindle 20 and the drive motor 620, enabling slip-free power transmission and ensuring accuracy and efficiency. Compared to traditional gear or chain drives, the synchronous belt assembly 610 distributes force more evenly and operates more smoothly, reducing energy loss during power transmission and improving the overall energy efficiency of the spindle structure. Furthermore, the non-rigid connection characteristic of the synchronous belt assembly 610 helps reduce noise and vibration during transmission, which is significant for improving machining accuracy and extending spindle lifespan. Especially under high-speed machining conditions, it can significantly reduce machining errors caused by vibration and ensure the surface quality of the workpiece.

[0035] Specifically, the synchronous belt assembly 610 includes a synchronous belt 611, a first transmission wheel 612 and a second transmission wheel 613, wherein the output end of the drive motor 620 is drivenly connected to the first transmission wheel 612, the second transmission wheel 613 is drivenly connected to the main shaft 20, and the synchronous belt 611 is sleeved on the first transmission wheel 612 and the second transmission wheel 613.

[0036] The coordination between the synchronous belt 611, the first transmission pulley 612, and the second transmission pulley 613 ensures that the power of the drive motor 620 is transmitted to the spindle 20 with high precision and synchronicity. This synchronicity guarantees the stability and machining accuracy of the spindle 20 under high-speed rotation, which is crucial for performing high-precision cutting operations. Furthermore, the layout design of the first transmission pulley 612 and the second transmission pulley 613 takes into account the space optimization inside the spindle box 10, allowing the drive motor 620 and the spindle 20 to be arranged non-coaxially. This creates space for the installation of other key components such as fluid transmission components, improving the compactness and integration of the spindle structure.

[0037] like Figure 2 As shown, the fluid transmission component 50 also includes a fluid switching valve 520, a fluid transmission pipe 530, and a rotary joint 540. The first inlet 510 of the fluid switching valve 520 is used to connect to the liquid supply tank. One end of the fluid transmission pipe 530 is connected to the outlet of the fluid switching valve 520, and the other end of the fluid transmission pipe 530 is connected to the inlet of the rotary joint 540. The outlet of the rotary joint 540 is connected to the central through hole of the spindle to deliver the coolant from the liquid supply tank to the central through hole of the spindle.

[0038] The fluid switching valve 520 in this application allows for rapid switching between coolant and gas, such as compressed air. This not only meets the coolant requirements during machining but also allows for the introduction of gas during tool changes and dry cutting operations, enabling multi-purpose fluid management and improving the adaptability and flexibility of the spindle structure. The first inlet 510 of the fluid switching valve 520 is connected to the coolant supply tank, allowing for precise control of the coolant flow and pressure, ensuring adequate cooling and lubrication of the cutting area and improving coolant utilization efficiency. The use of the rotary joint 540 solves the problem of coolant transmission when the spindle 20 rotates at high speed. The rotary joint 540 allows for a smooth transition of fluid between the rotating spindle center through-hole and the stationary fluid transmission pipe 530, ensuring stable coolant delivery at any speed and avoiding fluid leakage and pressure loss.

[0039] like Figure 4 As shown, the fluid transfer pipe 530 includes a first pipe section 531 and a second pipe section 532 that are perpendicular to each other and connected. The first pipe section 531 is connected to the fluid switching valve 520, and the second pipe section 532 is connected to the rotary joint 540 to deliver coolant into the rotary joint 540.

[0040] Preferably, the fluid transmission pipe 530 is divided into a first pipe section 531 and a second pipe section 532 that are perpendicular to each other. This vertical layout design reduces the number of bends in the fluid transmission process, thereby reducing the resistance to the flow of coolant and ensuring that the coolant can smoothly and quickly reach the rotary joint 540 from the fluid switching valve 520, thus improving the cooling effect and processing efficiency.

[0041] like Figure 3 and Figure 4 As shown, the fluid switching valve 520 is also provided with a second inlet 521, which is used to connect to an external gas supply component to send the high-pressure gas from the gas supply component into the rotary joint 540.

[0042] The second inlet 521 added in this application allows connection to an external gas supply component, which can not only provide high-pressure gas to clean the spindle tool holder interface during tool changes, but also be used in certain dry cutting or gas-cooled processes, realizing the multi-functionality and higher process adaptability of the spindle structure.

[0043] like Figure 2 and Figure 4 As shown, the spindle structure also includes a tie rod 40, which is disposed outside the spindle box 10 and located between the spindle 20 and the rotary joint 540. The rotating part of the rotary joint 540 is fixedly connected to the tie rod 40, and the tie rod 40 is provided with a tie rod center through hole for connecting the outlet of the rotary joint 540 with the spindle center through hole.

[0044] The central through-hole of the tie rod in this application ensures that the cutting fluid can flow directly and unobstructed from the rotary joint 540 to the central through-hole of the spindle, providing a more direct and precise coolant supply to the cutting area, improving cooling efficiency, reducing pressure loss of the cutting fluid, and ensuring temperature control and chip management during the machining process. Furthermore, the tie rod 40 is fixedly connected to the rotating part of the rotary joint 540. This design makes the movement of the tie rod 40 more precise and controllable when loosening and tightening the tool, ensuring a smooth and fast tool change process, reducing tool change time, and improving production efficiency.

[0045] Specifically, the spindle structure also includes a second drive component 70, which is disposed on the spindle box 10 and located on the side of the spindle box 10 away from the tool chuck 30. The second drive component 70 is driven to connect with the pull rod 40 to drive the pull rod 40 to move in the vertical direction.

[0046] The second drive component 70 in this application provides independent drive capability for the tie rod 40, separating its tool changing action from the rotational power of the spindle 20, thereby increasing the accuracy and reliability of the tool changing operation. This avoids the influence of spindle 20 rotation on the tool changing action, improving the stability of the tool changing process. Furthermore, the connection between the second drive component 70 and the tie rod 40 is designed on the side of the spindle box 10 away from the tool chuck 30. This layout reduces mechanical wear on the tool changing mechanism during spindle 20 rotation, extending the service life of the second drive component 70 and the entire spindle structure.

[0047] like Figure 2 As shown, the second drive component 70 includes a drive cylinder 710, a mounting assembly 720, and a first connector 730. The two ends of the mounting assembly 720 are respectively connected to the spindle box 10 and the fixed end of the drive cylinder 710. The output end of the drive cylinder 710 is drivenly connected to the first connector 730. The first connector 730 is sleeved on the rotary joint 540 and fixedly connected to the fixed part of the rotary joint 540, so that under the drive of the second drive component 70, the spindle 20 is driven to move along its own axis through the rotary joint 540.

[0048] In this application, the precise control capability of the drive cylinder 710 ensures high-precision movement of the pull rod 40 during tool loosening and tightening. The first connecting member 730 is connected to the fixed part of the rotary joint 540, ensuring the stability and accuracy of tool changing, reducing tool installation errors, and improving machining accuracy. The mounting assembly 720 ensures that the output force of the drive cylinder 710 is smoothly and losslessly transmitted to the first connecting member 730, thereby driving the precise movement of the rotary joint 540 and the pull rod 40. This efficient power transmission mechanism improves drive efficiency and reduces energy waste.

[0049] like Figure 4 As shown, the mounting assembly 720 includes a mounting plate 721 and mounting brackets 722. The mounting plate 721 is arranged along an axis perpendicular to the spindle 20. There are multiple mounting brackets 722, which are spaced apart between the mounting plate 721 and the spindle box 10 to connect the mounting plate 721 and the spindle box 10. The fixed end of the drive cylinder 710 is arranged on the mounting plate 721, and the first connector 730 is arranged in the mounting space 723 formed by the multiple mounting brackets 722.

[0050] The mounting plate 721, combined with multiple spaced mounting brackets 722, forms a stable mounting platform, ensuring the secure installation of the fixed end of the drive cylinder 710, reducing vibration and displacement during tool changing, and improving system stability. Furthermore, the mounting space 723 formed by the multiple mounting brackets 722 cleverly avoids the layout of other key components, such as the fluid transmission component 50, making the installation of the second drive component 70 more compact, reducing the demand on the internal space of the spindle box 10, and achieving efficient utilization of internal space.

[0051] The first connector 730 is provided with a clearance groove 731 for at least part of the fluid transmission component of the fluid transmission pipe 530, allowing the fluid transmission pipe 530 to pass through without affecting its normal operation, avoiding interference with the rotary joint 540 and other components, and improving the coordination and safety between components.

[0052] This application also provides a machine tool, including a spindle structure, which is the spindle structure described above.

[0053] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:

[0054] The spindle structure of this application includes a spindle box 10, a spindle 20, a fluid transmission component 50, and a first drive component 60. The fluid transmission component 50 is located on the side of the spindle box 10 away from the tool chuck 30 and connected to the spindle 20. The outlet of the fluid transmission component 50 is connected to the central through hole of the spindle, which effectively realizes the central transmission of cutting fluid or high-pressure gas. During machining, the coolant can directly act on the contact point between the tool and the workpiece, significantly improving the cooling effect and promoting timely chip removal. High-pressure gas can be used for cleaning and dry cutting operations during tool changes, enhancing the versatility of the spindle structure. In this application, the first drive component 60 is driven and connected to the spindle 20, and the rotation axis of the first drive component 60 is spaced apart from the axis of the spindle 20. This avoids the spatial limitations and interference problems caused by the coaxiality of the drive motor and the spindle in the traditional direct-drive spindle structure. This layout not only provides sufficient space to install fluid transmission components, but also ensures the stability and efficiency of the spindle during rotation, allowing the spindle to achieve central coolant supply while rotating. This provides more stable cooling conditions in complex and high-precision machining tasks, reduces the impact of thermal deformation, and improves machining accuracy and efficiency. It effectively solves the problem that machine tool spindles in the prior art cannot provide central water cooling at the contact point between the tool and the workpiece.

[0055] 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.

[0056] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0057] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0058] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0059] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0060] 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: Spindle box (10); A spindle (20) is mounted on the spindle box (10). One end of the spindle (20) is connected to the tool chuck (30). The spindle center through hole of the spindle (20) is connected to the chuck center through hole of the tool chuck (30). A fluid transmission component (50) is disposed on the side of the spindle box (10) away from the tool chuck (30) and connected to the spindle (20). The outlet of the fluid transmission component (50) is connected to the central through hole of the spindle. A first driving component (60) is disposed on the spindle box (10) and drivenly connected to the spindle (20) to drive the spindle (20) to rotate. The rotation axis of the first driving component (60) is spaced apart from the axis of the spindle (20).

2. The spindle structure according to claim 1, characterized in that, The spindle structure also includes a timing belt assembly (610), which is disposed inside the spindle housing (10). The driven end of the timing belt assembly (610) is connected to the spindle (20). The first driving component (60) is a drive motor (620), the fixed end of which is disposed on the spindle housing (10). The output end of the drive motor (620) is connected to the driving end of the timing belt assembly (610) to drive the spindle (20) to rotate through the timing belt assembly (610).

3. The spindle structure according to claim 2, characterized in that, The synchronous belt assembly (610) includes a synchronous belt (611), a first transmission wheel (612), and a second transmission wheel (613). The output end of the drive motor (620) is driven to the first transmission wheel (612), and the second transmission wheel (613) is driven to the main shaft (20). The synchronous belt (611) is sleeved on the first transmission wheel (612) and the second transmission wheel (613).

4. The spindle structure according to claim 1, characterized in that, The fluid transmission component (50) further includes a fluid switching valve (520), a fluid transmission pipe (530), and a rotary joint (540). The first inlet (510) of the fluid switching valve (520) is used to connect to the liquid supply tank. One end of the fluid transmission pipe (530) is connected to the outlet of the fluid switching valve (520), and the other end of the fluid transmission pipe (530) is connected to the inlet of the rotary joint (540). The outlet of the rotary joint (540) is connected to the central through hole of the spindle to deliver the coolant from the liquid supply tank to the central through hole of the spindle.

5. The spindle structure according to claim 4, characterized in that, The fluid transfer pipe (530) includes a first pipe section (531) and a second pipe section (532) that are perpendicular to each other and connected. The first pipe section (531) is connected to the fluid switching valve (520), and the second pipe section (532) is connected to the rotary joint (540) to deliver the coolant into the rotary joint (540); and / or, The fluid switching valve (520) is also provided with a second inlet (521), which is used to connect to an external gas supply component to send the high-pressure gas from the gas supply component into the rotary joint (540).

6. The spindle structure according to claim 4, characterized in that, The spindle structure also includes a tie rod (40), which is disposed outside the spindle box (10) and located between the spindle (20) and the rotary joint (540). The rotating part of the rotary joint (540) is fixedly connected to the tie rod (40), and the tie rod (40) is provided with a tie rod center through hole for connecting the outlet of the rotary joint (540) with the center through hole of the spindle.

7. The spindle structure according to claim 6, characterized in that, The spindle structure also includes a second drive component (70), which is disposed on the spindle box (10) and located on the side of the spindle box (10) away from the tool chuck (30). The second drive component (70) is driven to connect with the pull rod (40) to drive the pull rod (40) to move in the vertical direction.

8. The spindle structure according to claim 7, characterized in that, The second drive component (70) includes a drive cylinder (710), a mounting assembly (720), and a first connector (730). The two ends of the mounting assembly (720) are respectively connected to the spindle box (10) and the fixed end of the drive cylinder (710). The output end of the drive cylinder (710) is driven to connect to the first connector (730). The first connector (730) is sleeved on the rotary joint (540) and fixedly connected to the fixed part of the rotary joint (540) so that under the drive of the second drive component (70), the spindle (20) can be driven to move along its own axis through the rotary joint (540).

9. The spindle structure according to claim 8, characterized in that, The mounting assembly (720) includes a mounting plate (721) and mounting brackets (722). The mounting plate (721) is arranged along an axis perpendicular to the spindle (20). Multiple mounting brackets (722) are spaced apart between the mounting plate (721) and the spindle housing (10) to connect the mounting plate (721) and the spindle housing (10). The fixed end of the drive cylinder (710) is located on the mounting plate (721). The first connecting member (730) is located within the mounting space (723) formed by the multiple mounting brackets (722); and / or, The first connector (730) is provided with a clearance groove (731) for at least part of the fluid transmission component of the fluid transmission pipe (530).

10. A machine tool, characterized in that, Includes a spindle structure, wherein the spindle structure is the spindle structure according to any one of claims 1 to 9.

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