A screw cooling device for a numerical control machine tool

Abstract

The application discloses a screw cooling device for a numerical control machine tool, and belongs to the technical field of numerical control machine tools, which comprises a screw nut and a nut cooling jacket, wherein the nut cooling jacket comprises a shell and a shell cover; the shell is provided with a mounting cavity and a cooling cavity, the screw nut is embedded in the mounting cavity, and the mounting cavity penetrates through the shell; the cooling cavity is surrounded outside the mounting cavity, the cooling cavity is in a semi-closed structure, and the opening direction of the cooling cavity is towards the front of the screw nut; and the shell cover is used for closing the opening of the cooling cavity, so that the shell cover and the cooling cavity form a cooling space. By transferring the cooling object from the rotating screw to the relatively static screw nut, and by arranging the nut cooling jacket which is surrounded outside the screw nut, a sealed cooling space is formed inside the cooling jacket, the heat generated by the screw nut is taken away by circulating the cooling liquid in the space, so that the temperature and thermal elongation of the screw are indirectly controlled.

Description

Technical Field

[0001] This utility model relates to the field of CNC machine tool technology, and in particular to a lead screw cooling device for CNC machine tools. Background Technology

[0002] As a key transmission component in high-precision CNC machine tools, the operating accuracy of ball screw pairs directly affects the machining quality. During prolonged high-speed operation, friction and other factors generate a large amount of heat, causing the screw temperature to rise and resulting in thermal expansion. This thermal expansion alters the preload and effective length of the ball screw pair, significantly impacting the positioning accuracy and repeatability of the CNC machine tool. Particularly in high-precision machining applications, thermal expansion is a significant factor limiting the improvement of machining accuracy. To control this thermal expansion, existing technologies often employ internal cooling, which involves machining a continuous cooling channel at the center of the screw and circulating coolant through this channel via a rotary joint. However, because the screw rotates at high speed during operation, the connection between the coolant pipeline and the rotating screw must utilize a rotary seal structure. This rotary seal structure is typically complex in design, requires high manufacturing precision, and is prone to wear and failure under long-term high-speed rotation and coolant corrosion, greatly increasing the overall manufacturing difficulty, shortening its service life, and significantly raising manufacturing and maintenance costs. Therefore, existing technologies urgently need improvement to address these issues. Utility Model Content

[0003] This utility model discloses a lead screw cooling device for CNC machine tools, which aims to solve the problem of thermal elongation of CNC machine tool lead screws affecting machining accuracy.

[0004] This utility model discloses a lead screw cooling device for CNC machine tools, including a lead screw nut and a nut cooling sleeve. The nut cooling sleeve includes a housing and a cover. The housing has an installation cavity and a cooling cavity. The lead screw nut is embedded in the installation cavity, which extends through the housing. The cooling cavity surrounds the installation cavity and has a semi-closed structure with an opening. The cover is used to close the opening of the cooling cavity, forming a cooling space between the cover and the cooling cavity. The cover has two liquid guiding holes for coolant to be introduced into the cooling space from one hole and then discharged from the other hole. The cover has an installation hole for the lead screw nut to pass through. The housing and the cover are fixedly connected.

[0005] Furthermore, the opening of the cooling cavity faces the front of the lead screw nut.

[0006] Furthermore, the device also includes two liquid cooling pipes, which are respectively connected to the two liquid guiding holes of the housing cover.

[0007] Furthermore, the cover is provided with an annular boss that is embedded in the cooling cavity.

[0008] Furthermore, in the cooling cavity, a first sealing ring is provided between the outer side of the annular boss and the inner wall of one side of the cooling cavity.

[0009] Furthermore, in the cooling cavity, a second sealing ring is provided between the inner side of the annular boss and the inner wall of the other side of the cooling cavity.

[0010] Furthermore, the first sealing ring is installed on the annular boss.

[0011] Furthermore, the second sealing ring is installed on the annular boss.

[0012] Furthermore, the lead screw nut is fixedly connected to the housing by screws; the housing and the cover are fixedly connected by screws.

[0013] Furthermore, the mounting cavity is located at the center of the housing, and the cooling cavity has a hollow cylindrical structure surrounding the mounting cavity. Beneficial effects

[0014] This invention provides a lead screw cooling device for CNC machine tools. By transferring the cooling focus from the rotating lead screw to the relatively stationary lead screw nut, a nut cooling sleeve is installed around the lead screw nut. A sealed cooling space is formed inside this sleeve, and coolant circulates within this space to remove the heat generated by the lead screw nut, thereby indirectly controlling the temperature and thermal expansion of the lead screw. Compared to existing technologies that require cooling at the center of the rotating lead screw and use a rotary joint, the nut cooling sleeve of this invention is fixed relative to the machine tool body. The coolant piping does not require a complex rotary seal structure, effectively avoiding the problems of high manufacturing difficulty, short service life, and high cost associated with rotary seals. This device has a simple structure, is easy to manufacture and install, reduces production and maintenance costs, and improves the reliability and service life of the device. Simultaneously, by effectively cooling the lead screw nut, heat transfer to the lead screw is reduced, controlling the thermal expansion of the lead screw, thereby improving the machining accuracy and stability of the CNC machine tool. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the cooling device.

[0016] Figure 2 This is a cross-sectional view of AA in Figure 1.

[0017] Figure 3 This is a schematic diagram of the casing.

[0018] Figure 4 This is a schematic diagram of the shell cover.

[0019] Figure 5 This is a schematic diagram of the housing and the lead screw nut.

[0020] Labeling Explanation: 10, Screw Nut; 20, Housing; 30, Housing Cover; 40, Liquid Cooling Pipe; 21, Mounting Cavity; 22, Cooling Cavity; 31, Circular Boss; 32, Liquid Guide Hole; 33, First Sealing Ring; 34, Second Sealing Ring; 35, Mounting Hole; 36, First Groove; 37, Second Groove. Detailed Implementation

[0021] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] This application relates to the field of CNC machine tool technology, and more particularly to a ball screw cooling device for CNC machine tools. In precision CNC machine tools, the ball screw pair is a key component for achieving high-precision motion. However, during prolonged high-speed operation, the friction between the ball screw nut and the ball screw generates heat, causing the ball screw temperature to rise and thermal expansion to occur, thereby affecting the positioning accuracy and machining quality of the machine tool. Existing technologies typically attempt to control the ball screw temperature by setting up cooling channels inside the ball screw and circulating coolant, but this requires connecting the cooling pipes to the rotating ball screw through complex rotary joints, resulting in complex device structure, high manufacturing costs, and short service life. To overcome the shortcomings of existing technologies, this application proposes a new approach: indirectly controlling the ball screw temperature by cooling the ball screw nut, thereby providing a simple, low-cost, and long-service-life ball screw cooling device for CNC machine tools.

[0024] This application discloses a lead screw cooling device for CNC machine tools, which is mainly used in CNC machine tools to cool the lead screw nut 10 of the ball screw assembly, thereby controlling the thermal expansion of the lead screw and improving the machining accuracy of the machine tool. The device mainly includes the lead screw nut 10 and a nut cooling sleeve surrounding the lead screw nut 10. The nut cooling sleeve consists of a housing 20 and a cover 30.

[0025] Specifically, such as Figure 1 and Figure 2 As shown, the housing 20 is the main component of the nut cooling sleeve, and its interior is configured to have a mounting cavity 21 for accommodating the lead screw nut 10. This mounting cavity 21 is designed to penetrate the housing 20 to facilitate the installation and passage of the lead screw nut 10. Surrounding the mounting cavity 21, the housing 20 also has a cooling cavity 22. This cooling cavity 22 is configured to surround the mounting cavity 21, forming a space around the mounting position of the lead screw nut 10. Figure 2 and Figure 3 As shown, the cooling chamber 22 has a semi-closed structure, with its opening facing the front of the lead screw nut 10.

[0026] like Figure 2 As shown, the cover 30 is designed to close the opening of the cooling chamber 22 of the housing 20. When the cover 30 is fitted and fixed to the housing 20, the cover 30 and the cooling chamber 22 together form a closed cooling space for containing coolant. The cover 30 is provided with at least two liquid guiding holes 32, which communicate with the cooling space for the introduction and export of coolant, thereby realizing the circulation of coolant within the cooling space. In addition, the cover 30 also has a mounting hole 35 at its center, the size of which is designed to allow the front end of the lead screw nut 10 to pass through.

[0027] like Figure 2 and Figure 4 As shown, to ensure the airtightness of the cooling space and prevent coolant leakage, the cover 30 is provided with an annular boss 31 embedded in the cooling cavity 22. This annular boss 31 extends into the cooling cavity 22 when the cover 30 is engaged with the housing 20. Within the cooling cavity 22, a first sealing ring 33 is provided between the outer side of the annular boss 31 and one inner wall of the cooling cavity 22, and a second sealing ring 34 is provided between the inner side of the annular boss 31 and the other inner wall of the cooling cavity 22. These sealing rings, positioned between the annular boss 31 and the inner wall of the cooling cavity 22, achieve a reliable seal through their elastic deformation, thereby improving the airtightness of the cooling space.

[0028] The housing 20 and the cover 30 are connected together by a fixed method. For example, the cover 30 can be fixed to the front end of the housing 20 by screws. The lead screw nut 10, after being inserted into the mounting cavity 21 of the housing 20, can also be connected to the housing 20 by a fixed method, such as by screws. Furthermore, as... Figure 1 and Figure 2 As shown, the device also includes a liquid cooling pipe 40 connected to the liquid guiding hole 32 of the housing 30 for introducing and exporting coolant from the external cooling system.

[0029] Unlike existing technologies that require a rotary seal structure to cool the rotating lead screw, the technical solution of this application controls the temperature of the lead screw by cooling the relatively stationary lead screw nut 10. The nut cooling sleeve is fixed to the lead screw nut 10, which is typically fixed or undergoes linear motion relative to the machine tool body. Therefore, the connection between the coolant pipeline and the nut cooling sleeve does not require a complex rotary seal and can be directly fixed. This results in a simpler device structure, significantly reduced manufacturing costs, and avoids the wear and failure problems of rotary seals, improving the device's service life and reliability. By cooling the lead screw nut 10, which is the main heat source, heat is promptly removed, effectively reducing heat transfer to the lead screw or aiding in heat dissipation, thereby controlling the thermal elongation of the lead screw and ensuring the machining accuracy of the CNC machine tool.

[0030] When using the lead screw cooling device for CNC machine tools according to this application, the lead screw nut 10 generates frictional heat due to its high-speed movement on the lead screw. This heat is transferred to the housing 20 and cover 30 surrounding it through contact and conduction. Coolant is introduced into a liquid guide hole 32 of the cover 30 through a liquid guide pipe 40, entering the cooling space formed by the cooling chamber 22 and the cover 30. The coolant flows in this space, exchanging heat with the heated inner walls of the housing 20 and cover 30, absorbing heat. The coolant that has absorbed heat is discharged through another liquid guide hole 32 of the cover 30, via another liquid guide pipe 40, and flows back to the external cooling system for heat dissipation. Through the continuous circulation of coolant, the heat generated by the lead screw nut 10 is continuously carried away, thereby controlling the temperature of the lead screw nut 10 within the allowable range. Because the temperature of the lead screw nut 10 is controlled, the heat transferred to the lead screw is reduced, or heat dissipation is aided by the lead screw, thereby effectively suppressing the thermal elongation of the lead screw and ensuring the machining accuracy of the CNC machine tool under long-term working conditions. In this process, the housing 20 provides the mounting cavity 21 for mounting the lead screw nut 10 and the main structure forming the cooling cavity 22; the cover 30 seals the cooling cavity 22, forming a complete cooling space, and provides a channel for coolant to enter and exit and a mounting hole 35 through which the lead screw nut 10 passes; the annular boss 31, the first sealing ring 33 and the second sealing ring 34 ensure the sealing of the cooling space and prevent coolant leakage; the liquid guide hole 32 and the liquid guide cooling pipe 40 constitute the circulation path of the coolant; the fixed connection between the housing 20 and the cover 30 and the lead screw nut 10 and the housing 20 ensures the overall stability of the device and the effectiveness of heat transfer.

[0031] Furthermore, this application also proposes that the housing 20 and the cover 30 are fixedly connected by screws. Specifically, in this embodiment, the fixed connection between the housing 20 and the cover 30 is achieved by screws. Figure 3 and Figure 4 As shown, the housing 20 may have threaded holes for mounting screws, while the cover 30 has corresponding through holes. During assembly, the housing 20 and cover 30 are securely connected by passing screws through the through holes of the cover 30 and screwing them into the threaded holes of the housing 20. In a preferred embodiment, multiple screw holes can be provided at the front end of the housing 20, and the cover 30 can also have corresponding through holes, allowing the cover 30 to be fixed to the housing 20 using multiple screws. Screw connection is a widely used connection technology with advantages such as reliable connection, simple operation, ease of mass production, and convenient disassembly and reassembly when maintenance or component replacement is required. Therefore, using screw connection not only ensures the connection strength and sealing between the housing 20 and cover 30, but also greatly improves the manufacturing efficiency, installation convenience, and maintenance convenience of the CNC machine tool lead screw cooling device, thereby enhancing the overall practicality of the device.

[0032] Furthermore, this application also proposes that the device further includes two liquid cooling pipes 40, respectively connected to the two liquid guiding holes 32 of the housing cover 30. Specifically, as Figure 1 and Figure 2 As shown, in this embodiment, the CNC machine tool lead screw cooling device further includes two liquid cooling pipes 40. These two liquid cooling pipes 40 are respectively connected to two liquid guiding holes 32 provided on the housing cover 30. One liquid cooling pipe 40 serves as a coolant inlet pipe, used to introduce coolant from an external cooling system into the cooling space; the other liquid cooling pipe 40 serves as a coolant outlet pipe, used to discharge the coolant that has flowed through the cooling space and absorbed heat, returning it to the external cooling system for heat dissipation or treatment. The liquid cooling pipe 40 is connected to the liquid guiding hole 32 via a pipe joint, enabling reliable liquid sealing and smooth fluid passage. This arrangement allows coolant to be conveniently and effectively introduced and discharged from the cooling space, forming a complete coolant circulation path. Therefore, the device can be connected to a standard cooling system to achieve continuous coolant circulation, thereby ensuring continuous and effective cooling of the lead screw nut 10. Compared to the design that only sets liquid guiding holes on the shell cover 30, the addition of liquid guiding cooling pipes makes the cooling device a practical part of the cooling system, which greatly improves the functional integrity and practicality of the device and is an external connection structure necessary to realize its cooling function.

[0033] Furthermore, this application also proposes that the cover 30 is provided with an annular boss 31 embedded in the cooling cavity 22. Specifically, as Figure 2 and Figure 4 As shown, in this embodiment, the cover 30 is provided with an annular boss 31, which is configured to embed into the cooling cavity 22 of the housing 20. The annular boss 31 is part of the cover 30, and its shape and size mate with the inner wall of the cooling cavity 22. When the cover 30 is assembled with the housing 20, the annular boss 31 extends into the cooling cavity 22. This design of the annular boss 31, compared to a solution relying solely on planar fit, more effectively achieves precise alignment and positioning between the housing 20 and the cover 30. This precise positioning is crucial for the subsequent installation of the seals, ensuring that the seals can be correctly compressed and installed in the predetermined position, thereby greatly improving the sealing reliability of the cooling space and effectively preventing coolant leakage. Therefore, the design of the annular boss 31 is one of the key structural features for achieving reliable sealing of the cooling device, making a significant contribution to improving the overall performance and stability of the device.

[0034] Furthermore, this application also proposes that a first sealing ring 33 be provided between the outer side of the annular boss 31 and the inner wall of one side of the cooling cavity 22. Specifically, as follows... Figure 2As shown, in this embodiment, within the cooling space formed by the cooling cavity 22 of the housing 20 and the housing cover 30, a first sealing ring 33 is provided between the outer periphery of the annular boss 31 on the housing cover 30 and one inner wall of the cooling cavity 22. The first sealing ring 33 is installed on the outer periphery of the annular boss 31 or at a corresponding position in the cooling cavity 22. When the housing cover 30 is assembled and fixed with the housing 20, the first sealing ring 33 is compressed, thereby forming a reliable sealing line between the outer side of the annular boss 31 and the inner wall of the cooling cavity 22. The first sealing ring 33 can be made of an elastic material with a circular cross-sectional shape (such as an O-ring). The first sealing ring 33 provides a first sealing barrier on the outer periphery of the annular boss 31.

[0035] Furthermore, this application also proposes that a second sealing ring 34 be provided between the inner side of the annular boss 31 and the inner wall of the other side of the cooling cavity 22. Specifically, as follows... Figure 2 As shown, in this embodiment, within the cooling space formed by the cooling cavity 22 of the housing 20 and the housing cover 30, a second sealing ring 34 is provided between the inner periphery of the annular boss 31 on the housing cover 30 and the inner wall of the cooling cavity 22 on the other side. The second sealing ring 34 is installed on the inner periphery of the annular boss 31 or at a corresponding position in the cooling cavity 22. When the housing cover 30 is assembled and fixed with the housing 20, the second sealing ring 34 is compressed, thereby forming another reliable sealing line between the inner side of the annular boss 31 and the inner wall of the cooling cavity 22. The second sealing ring 34 can be made of the same elastic material and cross-sectional shape as the first sealing ring 33, such as an O-ring. The second sealing ring 34 provides a second sealing barrier on the inner periphery of the annular boss 31. Thus, by simultaneously providing the first sealing ring 33 and the second sealing ring 34, an effective seal is formed on both the outer and inner sides of the annular boss 31, constituting a double sealing structure. This double-sealing structure greatly improves the sealing reliability of the cooling space and is a key structure to ensure that the coolant can circulate stably in the cooling space without leakage. It is of great significance for ensuring the normal operation and cooling effect of the lead screw cooling device for CNC machine tools.

[0036] Furthermore, this application also proposes that the first sealing ring 33 be mounted on the annular boss 31. Specifically, in this embodiment, the first sealing ring 33 is mounted on the outer peripheral surface of the annular boss 31 provided on the cover 30. Figure 4As shown, the outer peripheral surface of the annular boss 31 may be provided with an annular first groove 36 for accommodating the first sealing ring 33, which is placed into the first groove 36. Thus, when assembling the cover 30 with the housing 20, the annular boss 31 can guide the first sealing ring 33 accurately into the corresponding position of the cooling cavity 22, ensuring that the first sealing ring 33 is correctly positioned and compressed between the outer side of the annular boss 31 and one inner wall of the cooling cavity 22. The first groove 36 provides reliable support and precise positioning for the first sealing ring 33, preventing displacement or twisting of the sealing ring during assembly. Therefore, it can be ensured that the first sealing ring 33 receives appropriate compression after the housing 20 and the cover 30 are fixedly connected, thereby forming a stable and reliable seal. Compared to the scheme that only limits the first sealing ring 33 to the area between the outer side of the annular boss 31 and the inner wall of the cooling cavity 22, installing the first sealing ring 33 on the annular boss 31 greatly improves the accuracy and reliability of the sealing installation, further enhances the sealing performance of the cooling space, and effectively prevents coolant leakage.

[0037] Furthermore, this application also proposes that the second sealing ring 34 be mounted on the annular boss 31. Specifically, as Figure 2 As shown, in this embodiment, the second sealing ring 34 is mounted on the inner circumferential surface of the annular boss 31 provided on the cover 30. Figure 4 As shown, the inner circumferential surface of the annular boss 31 may be provided with an annular second groove 37 for accommodating the second sealing ring 34, which is placed into the second groove 37. Thus, when assembling the cover 30 with the housing 20, the annular boss 31 can guide the second sealing ring 34 accurately into the corresponding position of the cooling cavity 22, ensuring that the second sealing ring 34 is correctly positioned and compressed between the inner side of the annular boss 31 and the inner wall of the cooling cavity 22 on the other side. The second groove 37 provides reliable support and precise positioning for the second sealing ring 34, preventing displacement or twisting of the sealing ring during assembly. Therefore, it can be ensured that the second sealing ring 34 receives appropriate compression after the housing 20 and the cover 30 are fixedly connected, thereby forming a stable and reliable seal. Compared to the scheme that only limits the second sealing ring 34 to the inner side of the annular boss 31 and the inner wall of the cooling cavity 22, installing the second sealing ring 34 on the annular boss 31 greatly improves the accuracy and reliability of the sealing installation, further enhances the sealing performance of the cooling space, effectively prevents coolant leakage, and together with the first sealing ring 33, forms a more reliable double sealing structure.

[0038] Furthermore, this application also proposes that the lead screw nut 10 be fixedly connected to the housing 20 by screws. Specifically, in this embodiment, after the lead screw nut 10 is inserted into the mounting cavity 21 of the housing 20, it is fixedly connected to the housing 20 by screws. Figure 5 As shown, the end of the lead screw nut 10 can be provided with a structure for mounting screws, such as a countersunk hole, and the rear end of the housing 20 is also provided with corresponding screw holes. By passing the screw through the countersunk hole of the lead screw nut 10 and screwing it into the screw hole of the housing 20, the lead screw nut 10 can be firmly fixed to the housing 20. This connection method provides reliable mechanical fixation, ensuring that the lead screw nut 10 maintains a stable position within the mounting cavity 21 of the housing 20 and will not loosen or shift during use. More importantly, the tight fixation achieved by the screw connection ensures good thermal contact between the lead screw nut 10 and the housing 20, which is conducive to the efficient transfer of heat generated by the lead screw nut 10 to the housing 20, and then being carried away by the coolant in the cooling cavity 22. Thus, this screw-fixed connection scheme not only improves the structural stability of the device, but is also a key means to ensure effective heat transfer and achieve good cooling effect. At the same time, it also makes the entire nut cooling sleeve and the lead screw nut 10 form a compact and stable whole, which is convenient for installation on CNC machine tools.

[0039] Furthermore, this application also proposes that the mounting cavity 21 is located at the center of the housing, and the cooling cavity 22 has a hollow cylindrical structure surrounding the mounting cavity 21. Specifically, as Figure 2 As shown, in this embodiment, the mounting cavity 21 inside the housing 20 is configured to be located at the center of the housing 20. Figure 3 As shown, a mounting cavity 21 is installed around the center, and a cooling cavity 22 is constructed as a hollow cylinder and surrounds the periphery of the mounting cavity 21. The mounting cavity 21 is located at the center of the housing 20, meaning that when the lead screw nut 10 is installed in this cavity, its central axis is substantially coincident with the central axis of the housing 20. The hollow cylindrical structure of the cooling cavity 22 surrounding the mounting cavity 21 forms an annular cooling space that is evenly distributed around the outer periphery of the lead screw nut 10. By placing the mounting cavity 21 at the center and constructing the cooling cavity 22 as a hollow cylinder surrounding it, a symmetrical and uniform annular cooling space is formed, ensuring that the coolant can flow evenly through the nut cooling sleeve, thereby allowing for sufficient and uniform heat exchange between the coolant and the lead screw nut 10 indirectly. Therefore, this solution enables more efficient and uniform cooling of the lead screw nut 10, avoids local overheating, and further improves the cooling effect and the accuracy of lead screw temperature control. This plays an important role in ensuring the machining accuracy of CNC machine tools under high load and long-term operation.

[0040] The above descriptions are merely some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this utility model, and all such modifications and improvements fall within the protection scope of this utility model.

Claims

1. A lead screw cooling device for CNC machine tools, characterized in that, include: Screw nut (10); And a nut cooling sleeve, the nut cooling sleeve including a housing (20) and a cover (30); The housing (20) is provided with a mounting cavity (21) and a cooling cavity (22). The lead screw nut (10) is embedded in the mounting cavity (21), and the mounting cavity (21) penetrates the housing (20). The cooling cavity (22) surrounds the periphery of the mounting cavity (21), the cooling cavity (22) has a semi-closed structure, and the cooling cavity (22) is provided with an opening; The cover (30) is used to close the opening of the cooling cavity (22), so that the cover (30) and the cooling cavity (22) form a cooling space; The cover (30) is provided with two liquid guiding holes (32) for coolant to be introduced into the cooling space from one of the liquid guiding holes (32) and then discharged from the other liquid guiding hole (32); The cover (30) is provided with a mounting hole (35) through which the lead screw nut (10) passes; The housing (20) is fixedly connected to the cover (30).

2. The lead screw cooling device for CNC machine tools according to claim 1, characterized in that, The opening of the cooling cavity (22) faces the front of the lead screw nut (10).

3. The lead screw cooling device for CNC machine tools according to claim 1, characterized in that, The device also includes two liquid cooling pipes (40), which are respectively connected to the two liquid guiding holes (32) of the housing cover (30).

4. The lead screw cooling device for CNC machine tools according to claim 1, characterized in that, The cover (30) is provided with an annular boss (31) embedded in the cooling cavity (22).

5. The lead screw cooling device for CNC machine tools according to claim 4, characterized in that, In the cooling cavity (22), a first sealing ring (33) is provided between the outer side of the annular boss (31) and the inner wall of one side of the cooling cavity (22).

6. The lead screw cooling device for CNC machine tools according to claim 4, characterized in that, In the cooling cavity (22), a second sealing ring (34) is provided between the inner side of the annular boss (31) and the inner wall of the other side of the cooling cavity (22).

7. The lead screw cooling device for CNC machine tools according to claim 5, characterized in that, The first sealing ring (33) is mounted on the annular boss (31).

8. The lead screw cooling device for CNC machine tools according to claim 6, characterized in that, The second sealing ring (34) is installed on the annular boss (31).

9. The lead screw cooling device for CNC machine tools according to claim 1, characterized in that, The lead screw nut (10) is fixedly connected to the housing (20) by screws; the housing (20) and the cover (30) are fixedly connected by screws.

10. The lead screw cooling device for CNC machine tools according to claim 1, characterized in that, The mounting cavity (21) is located at the center of the housing (20), and the cooling cavity (22) has a hollow cylindrical structure surrounding the mounting cavity (21).

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