Lead screw drive for a numerically controlled machine tool

Abstract

The application discloses a screw rod transmission device for a numerical control machine tool, and belongs to the technical field of machine tool transmission devices.The screw rod transmission device comprises an operation table, a screw rod, a workbench, a main nut, a secondary nut, a mounting piece and a main positioning column.The screw rod is rotationally connected to the operation table, and the workbench is slidably connected to the operation table.The main nut is threadedly connected to the screw rod and fixedly connected to the workbench.The screw rod is threadedly connected with the secondary nut.The opposite sides of the main nut and the secondary nut are fixedly connected with the main positioning column and the secondary positioning column, respectively.The mounting piece is sealingly and slidably connected to the main positioning column.The adjustment mode of the pre-tightening force of the double nuts is changed, and a through hole extending to the mounting piece is formed in the workbench, so that the gap of the double nuts can be directly adjusted without removing the workbench, the pre-tightening force of the double nuts is changed, the step of adjusting the pre-tightening force is reduced, the efficiency of the maintenance work is improved, and the working efficiency of the numerical control machine tool is improved.

Description

Technical Field

[0001] This invention relates to the field of machine tool transmission technology, and more particularly to a lead screw transmission device for CNC machine tools. Background Technology

[0002] The lead screw transmission device on a CNC machine tool is one of the key components for achieving high-precision and high-efficiency feed motion of the CNC machine tool table. It mainly consists of a ball screw and a nut seat fixed to the worktable. The surface of the ball screw and the hole wall of the nut seat are both spiral guide grooves. The balls are arranged one by one in the rolling channel formed by the lead screw and the nut seat to achieve high-speed and high-precision transmission.

[0003] Due to factors such as machining accuracy, assembly errors, and wear, axial clearance exists between the balls and their rolling channels. This causes a backlash error when the lead screw rotates in the reverse direction, resulting in a deviation between the actual and target movement distances of the worktable. This leads to increased machining errors and reduced machining accuracy of the CNC machine tool. Currently, double-nut preload is used to eliminate backlash errors. There are two main methods for applying preload to the double nuts: one is to add shims between the double nuts, and the other is to install an elastic body between the double nuts. However, regardless of the method, as the CNC machine tool is used for a longer period, the ball screw, nut seat, and balls will all wear, causing the axial clearance between the balls and the rolling channels to increase again, resulting in reduced machining accuracy of the CNC machine tool. At this point, the preload of the double nuts needs to be readjusted. However, both of the above methods of applying preload to the double nuts require the removal of the worktable to adjust the preload between the double nuts. The operation steps are cumbersome, the workload is large, and the maintenance efficiency is low, resulting in low machining efficiency of the CNC machine tool. Summary of the Invention

[0004] This invention provides a lead screw transmission device for CNC machine tools, which overcomes the shortcomings of existing CNC machine tools where adjusting the preload between the two nuts requires removing the worktable due to wear, resulting in a large workload and low maintenance efficiency.

[0005] The technical embodiment of the present invention is as follows: a lead screw transmission device for CNC machine tools, comprising:

[0006] An operating table is rotatably connected to a lead screw and slidably connected to a worktable, the worktable being provided with an extension hole;

[0007] The main nut is threaded to the lead screw and fixed to the worktable. The lead screw is threaded to a secondary nut. The main nut and the secondary nut are respectively fixed to the opposite sides of the main nut and the secondary nut.

[0008] The mounting component is slidably connected to the main positioning post and fixedly connected to the secondary positioning post. The mounting component is in contact with the secondary nut. The mounting component is provided with an adjustment hole, and the central axis of the adjustment hole is collinear with the central axis of the extension hole.

[0009] An adjustment component, disposed on the mounting member, is used to adjust the gap between the main nut and the secondary nut via the extension hole.

[0010] Furthermore, the adjustment component includes:

[0011] The intermediate component is rotatably connected to the mounting component, and an adjusting rod is rotatably connected inside the adjusting hole. The adjusting rod and the intermediate component form a worm gear structure.

[0012] An extruded component is threadedly connected to the mounting component and splinedly connected to the intermediate component.

[0013] Furthermore, the cross-sectional shape at the spline connection between the extruder and the transfer member is an isosceles trapezoid, and the width of the isosceles trapezoid gradually increases in the direction that gradually approaches the central axis of the extruder.

[0014] Furthermore, it also includes:

[0015] Multiple main locating pins are fixed to the side of the extrusion member near the main nut, and multiple secondary locating pins are fixed to the side of the main nut near the extrusion member.

[0016] Several elastic elements are disposed between the main nut and the pressing element, and are respectively fixed to the adjacent main locating pin and the adjacent secondary locating pin. The number of elastic elements is not greater than the number of main locating pins, and the number of elastic elements is not greater than the number of secondary locating pins.

[0017] Furthermore, there is a distance between the mounting component and the main nut.

[0018] Furthermore, the central angle corresponding to the projection of the elastic element onto the end face of the main nut, with the center point of the end face of the main nut as the center, is less than 180°.

[0019] Furthermore, it also includes:

[0020] An installation ring is slidably connected to the mounting component, and a wedge is fixedly connected to the installation ring. A pressurized flow channel is provided inside the mounting component along its central axis. The main positioning post slides and seals within the pressurized flow channel. A sealing post is slidably connected to the mounting component near the wedge. The wedge is used to squeeze the sealing post. The sealing post divides the pressurized flow channel into two parts. The sealing post is provided with a connecting hole, which is used to connect the pressurized flow channel that is separated by the sealing post.

[0021] An elastic cylinder is fixedly attached to a portion of the pressurized flow channel away from the main positioning post.

[0022] The sealing pin is detachably connected to one end of the pressurized flow channel near the secondary nut.

[0023] Furthermore, a pre-compression component is slidably connected to the side of the mounting component near the sealing post, and an extrusion plate is fixedly connected to the sealing post, the extrusion plate being used to compress the pre-compression component.

[0024] Furthermore, the wedge pushes the sealing post to move by its inclined surface, the height of the inclined surface of the wedge in the direction of the central axis of the sealing post being greater than the diameter of the connecting hole.

[0025] Furthermore, the mounting ring is rotatably connected to a dustproof ring, and the minimum distance between the dustproof ring and the central axis of the lead screw is less than the radius of the lead screw.

[0026] Compared with the prior art, the present invention has the following advantages: By changing the adjustment method of the preload of the double nuts and opening through holes on the worktable extending to the mounting part, the gap of the double nuts can be directly adjusted without removing the worktable, thereby changing the preload of the double nuts. This reduces the steps of adjusting the preload and improves the efficiency of maintenance work, which is conducive to improving the working efficiency of CNC machine tools.

[0027] By changing the compression amount of the elastic element through the movement of the extruder, users can easily adjust the preload between the two nuts according to their own needs. At the same time, by using two elastic elements to replace the elastomer in the existing technology, it is easier to replace the elastic element and improve the efficiency of maintenance work.

[0028] By blocking the flow path of hydraulic oil, the distance between the main nut and the mounting part is locked. This offsets part of the squeezing force on the elastic element when the table movement resistance is high, reducing the probability of deformation of the elastic element, and thus keeping the relative position of the main nut and the auxiliary nut unchanged, thereby maintaining the stability of the machining accuracy of the CNC machine tool. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0030] Figure 2 This is a three-dimensional structural diagram of the lead screw, main nut, and auxiliary nut of the present invention;

[0031] Figure 3 This is a three-dimensional structural diagram of the main nut, auxiliary nut, and mounting component of the present invention;

[0032] Figure 4This is an exploded view of the main nut, secondary nut, and mounting component of the present invention;

[0033] Figure 5 This is a three-dimensional structural diagram of the transfer component and adjusting lever in this invention;

[0034] Figure 6 This is a three-dimensional structural cross-sectional view of the mounting component and the transfer component of the present invention;

[0035] Figure 7 This is a three-dimensional structural cross-sectional view of the mounting component and the extrusion component of the present invention;

[0036] Figure 8 This is a three-dimensional structural diagram of the extrusion member and the elastic member of the present invention;

[0037] Figure 9 This is a three-dimensional structural cross-sectional view of the mounting component and mounting ring of the present invention;

[0038] Figure 10 Appendix to this invention Figure 9 Enlarged view of point A in the middle.

[0039] The components in the attached diagram are labeled as follows: 1-Operating table, 2-Lead screw, 3-Workbench, 301-Extension hole, 4-Main nut, 401-Main positioning pin, 5-Secondary nut, 501-Secondary positioning pin, 6-Mounting component, 601-Adjusting hole, 7-Transfer component, 8-Adjusting rod, 9-Extrusion component, 10-Elastic component, 101-Main positioning pin, 102-Secondary positioning pin, 11-Mounting ring, 12-Wedge block, 121-Pressurized flow channel, 13-Sealing pin, 131-Connecting hole, 14-Elastic cylinder, 15-Sealing pin, 16-Pre-compression component, 17-Extrusion plate, 18-Dustproof ring. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] A lead screw drive device for CNC machine tools, see [link / reference] Figures 1-6The system includes: an operating table 1, which is rotatably connected to a lead screw 2 and slidably connected to a worktable 3, the worktable 3 having an extension hole 301; a main nut 4, threadedly connected to the lead screw 2 and fixedly connected to the worktable 3, the lead screw 2 being threadedly connected to a secondary nut 5, the main nut 4 and the secondary nut 5 having a main positioning post 401 and a secondary positioning post 501 respectively fixedly connected to their opposing sides; a mounting component 6, which is slidably and sealed to the main positioning post 401 and fixedly connected to the secondary positioning post 501, the mounting component 6 contacting the secondary nut 5, the mounting component 6 having an adjustment hole 601, the central axis of the adjustment hole 601 being collinear with the central axis of the extension hole 301; and an adjustment assembly, mounted on the mounting component 6, used to adjust the gap between the main nut 4 and the secondary nut 5 through the extension hole 301.

[0042] The above solution aims to address the problem that adjusting the preload between the two nuts on existing CNC machine tools requires removing the worktable, resulting in a large workload and low maintenance efficiency. This solution changes the method of adjusting the preload of the two nuts and creates a through hole on the worktable 3 extending to the mounting part 6. This allows for direct adjustment of the gap between the two nuts without removing the worktable 3, thereby changing the preload. This reduces the steps required to adjust the preload and improves maintenance efficiency, ultimately enhancing the working efficiency of the CNC machine tool.

[0043] The number of main positioning pins 401 and secondary positioning pins 501 can be adjusted according to actual conditions. In this paper, there are two main positioning pins 401 and two secondary positioning pins 501, which are used to prevent relative rotation between the main nut 4 and the secondary nut 5 through the mounting part 6. When there is no need to adjust the preload, the upper part of the extension hole 301 can be blocked by rubber plugs to prevent machining debris and coolant from entering the extension hole 301 when the CNC machine tool is working. The diameter of the extension hole 301 is larger than the diameter of the adjustment hole 601, so that the projection of the adjustment hole 601 on the horizontal plane can always be located within the projection of the extension hole 301 on the horizontal plane.

[0044] See Figures 4-7 The adjustment assembly includes: a transfer member 7, which is rotatably connected to the mounting member 6, and an adjustment rod 8 is rotatably connected in the adjustment hole 601. The adjustment rod 8 and the transfer member 7 form a worm gear structure; an extrusion member 9, which is threadedly connected to the mounting member 6 and splinedly connected to the transfer member 7; the cross-sectional shape of the spline connection between the extrusion member 9 and the transfer member 7 is an isosceles trapezoid, and the width of the isosceles trapezoid gradually increases in the direction that gradually approaches the central axis of the extrusion member 9.

[0045] In the above scheme, the aim is to drive the extrusion part 9 to rotate and control the telescopic movement of the extrusion part 9 through a worm gear, thereby controlling the gap between the main nut 4 and the secondary nut 5. On the one hand, it eliminates the need for frequent disassembly and assembly of shims when adjusting the preload, saving adjustment steps. On the other hand, the self-locking performance of the worm gear ensures the stability of the gap between the main nut 4 and the secondary nut 5. The adjusting rod 8 can be rotatably connected to the adjusting hole 601 by means of a snap ring. The cross section of the spline connection between the extrusion part 9 and the intermediate transfer part 7 is an isosceles trapezoid, which improves the stability of the connection between the extrusion part 9 and the intermediate transfer part 7, while enhancing the structural strength of the intermediate transfer part 7 and helping to suppress the deformation of the spline connection position of the intermediate transfer part 7.

[0046] See Figures 4-6 and Figure 8 It also includes: multiple main locating pins 101, all fixed to the side of the extrusion member 9 near the main nut 4, and multiple secondary locating pins 102 fixed to the side of the main nut 4 near the extrusion member 9; several elastic members 10, all disposed between the main nut 4 and the extrusion member 9, and fixed to adjacent main locating pins 101 and adjacent secondary locating pins 102 respectively, the number of elastic members 10 is not greater than the number of main locating pins 101, and the number of elastic members 10 is not greater than the number of secondary locating pins 102; there is a distance between the mounting member 6 and the main nut 4; the central angle corresponding to the projection of the elastic member 10 on the end face of the main nut 4 with the center point of the end face of the main nut 4 as the center is less than 180°.

[0047] There are two existing methods for applying preload to double nuts. One method involves adding a shim between the double nuts and adjusting its thickness to cause the double nuts to shift axially in opposite directions, thus achieving preload. However, this method requires repeated adjustments to the shim thickness and repeated installation and removal of the shim, making the operation cumbersome. The second method involves installing an elastomer between the double nuts and using the elastomer to apply a backward compressive force along the axial direction to achieve preload. This method can accommodate situations where the axial clearance increases due to wear of the ball screw and balls. However, with increased usage time, the elastomer may experience fatigue due to prolonged compression, reducing the compressive force it exerts on the double nuts. In this case, the double nuts need to be removed from the ball screw and the elastomer replaced, which is also cumbersome.

[0048] The above solution aims to address the problems of cumbersome replacement procedures and the fact that the preload force applied to the double nuts by the elastomer is pre-set at the factory, preventing users from adjusting it. This solution utilizes the movement of the compression member 9 to change the compression amount of the elastic member 10, allowing users to easily adjust the preload force between the double nuts. Furthermore, using two elastic members 10 instead of the elastomer facilitates replacement and improves maintenance efficiency. The number of elastic members 10 is two. Each elastic element 10 consists of three arc-shaped plates and several support blocks. The arc-shaped plates of the elastic element 10 are made of elastic metal. The support blocks of the elastic element 10 are fixed in the gap between two adjacent arc-shaped plates. The support blocks in the two gaps formed by the three arc-shaped plates are staggered. When the elastic element 10 is compressed, the arc-shaped plates on the elastic element 10 can deform, which can function like a spring. The central angle of the elastic element 10 is less than 180°, which allows the elastic element 10 to be replaced without removing the main nut 4 and the secondary nut 5 from the lead screw 2.

[0049] The working principle of the above scheme is as follows: When the CNC machine tool is working, the control screw 2 rotates, and the screw 2 drives the main nut 4 and the auxiliary nut 5 to move together. The main nut 4 drives the worktable 3 to move. When it is necessary to adjust the preload between the main nut 4 and the auxiliary nut 5, a tool is inserted into the extension hole 301 and contacts the adjusting rod 8 (this article takes the need to increase the preload as an example). Then, the adjusting rod 8 is rotated by the tool, and the adjusting rod 8 drives the intermediate rotating component 7 to rotate. The intermediate rotating component 7 drives the pressing component 9 to rotate through the spline. The pressing component 9 moves to the right under the action of the thread, increasing the pressing force of the pressing component 9 on the elastic component 10, causing the elastic component 10 to deform. The elastic component 10 presses the main nut 4 to the right. At the same time, the elastic component 10 is pressed by the pressing component. 9. The intermediate component 7 and the mounting component 6 press the secondary nut 5 to the left. Since the main nut 4 and the secondary nut 5 cannot rotate relative to each other, the balls inside the main nut 4 and the secondary nut 5 are pressed and moved. This causes the balls in the secondary nut 5 to contact the right side of its upper guide groove and the left side of the upper guide groove of the lead screw 2 (the cross-section of the guide groove in the vertical plane is a semi-circular groove, and the left and right sides here refer to the left and right sides of the semi-circular groove where the balls are located). The balls in the main nut 4 contact the left side of its upper guide groove and the right side of the upper guide groove of the lead screw 2, providing preload to the main nut 4 and the secondary nut 5. This eliminates the axial clearance between the balls and the rolling channel, improves the transmission accuracy, and thus ensures the machining accuracy and efficiency of the CNC machine tool.

[0050] See Figure 7 , Figure 9 and Figure 10It also includes: a mounting ring 11, which is slidably connected to the mounting component 6, and a wedge 12 is fixedly connected to the mounting ring 11. The mounting component 6 is provided with a pressurizing channel 121 that runs through it along its central axis. The main positioning post 401 is sealed and slidably connected to the pressurizing channel 121. A sealing post 13 is sealed and slidably connected to the side of the mounting component 6 near the wedge 12. The wedge 12 is used to squeeze the sealing post 13. The sealing post 13 divides the pressurizing channel 121 into two parts. The sealing post 13 is provided with a connecting hole 131, which is used to connect the pressurizing channel 121 that is separated by the sealing post 13; an elastic cylinder 14, which is fixedly connected to a part of the pressurizing channel 121 away from the main positioning post 401; and a sealing pin 15, which is detachably connected to the end of the pressurizing channel 121 near the secondary nut 5.

[0051] The above solution aims to address the problem that existing methods, which use an elastomer installed between two nuts to provide preload, suffer from compressibility issues. When the CNC machine tool table experiences high movement resistance, the elastomer can be compressed, causing a deviation between the distance the table moves and the target movement distance. This solution blocks the flow path of the hydraulic oil, locking the distance between the main nut 4 and the mounting component 6. This counteracts some of the pressure on the elastomer 10 when the table 3 experiences high movement resistance, reducing the probability of deformation and maintaining the relative position of the main nut 4 and the secondary nut 5. This ensures stable machining accuracy of the CNC machine tool.

[0052] The reasons for machining errors in CNC machine tools caused by the use of elastomers are as follows: When the lead screw drives the worktable to move to one side, the guide groove of the lead screw directly squeezes the balls in the main nut, driving the main nut to move the worktable. During this period, the elastomer maintains that there is no relative rotation between the main nut and the secondary nut, allowing the secondary nut to move along with the main nut. When the lead screw drives the worktable to move to the other side, the guide groove of the lead screw directly squeezes the balls in the secondary nut. At this time, the secondary nut moves along with the main nut through the elastomer. If the resistance on the worktable connected to the main nut is too great, the elastomer between the main and secondary nuts will be compressed, reducing the gap between the main and secondary nuts. In this case, the distance the main nut moves is less than the distance the secondary nut moves, i.e., the distance the main nut does not need to move, thus causing machining errors in the CNC machine tool.

[0053] The main positioning pin 401, pressurized flow channel 121, elastic cylinder 14, and sealing pin 15 form a hydraulic chamber. After the main positioning pin 401 is inserted into the mounting part 6, the sealing pin 15 can be removed and hydraulic oil can be injected into the hydraulic chamber to fill the entire chamber. A sealing ring is installed on the sealing pin 15 to form a sealing surface between the sealing pin 15 and the pressurized flow channel 121. The elastic cylinder 14 is made of elastic rubber. The inner diameter of the pressurized flow channel 121 near the elastic cylinder 14 is larger than the outer diameter of the elastic cylinder 14, allowing the elastic cylinder 14 to deform. The elastic cylinder 14 can maintain the stability of the pressure in the hydraulic chamber when the relative position between the main positioning pin 401 and the mounting part 6 changes, without affecting the main nut 4 and the mounting part 6. The relative movement between the components 6; the sealing column 13 divides the hydraulic chamber into left and right parts, with the elastic cylinder 14 located in the left hydraulic chamber and the main positioning column 401 located in the right hydraulic chamber; there is air between the upper side of the sealing column 13 and the mounting component 6, so that the sealing column 13 can be reset under air pressure after movement; the number of wedges 12, sealing columns 13, elastic cylinders 14 and sealing pins 15 is determined according to the number of main positioning columns 401. In this paper, the number of wedges 12, sealing columns 13, elastic cylinders 14 and sealing pins 15 are all two; the sealing column 13 and the main positioning column 401 maintain a sealed sliding relationship with the mounting component 6 through the sealing ring; initially, the mounting ring 11 is located at the right limit position inside the mounting component 6.

[0054] See Figure 9 and Figure 10 A pre-compression component 16 is slidably connected to the side of the mounting component 6 near the sealing column 13. The sealing column 13 is fixedly connected to a compression plate 17, which is used to compress the pre-compression component 16. The wedge block 12 compresses the sealing column 13 through its inclined surface. The height of the inclined surface of the wedge block 12 in the direction of the central axis of the sealing column 13 is greater than the diameter of the connecting hole 131. The mounting ring 11 is rotatably connected to a dustproof ring 18. The minimum distance between the dustproof ring 18 and the central axis of the lead screw 2 is less than the radius of the lead screw 2.

[0055] In the above scheme, the aim is to isolate the left and right sides of the hydraulic chamber by using the sealing column 13, and then increase the pressure in the right hydraulic chamber by moving the pre-compression member 16. This causes the sealing rings on the main positioning column 401 and the sealing column 13 to deform, increasing the resistance of the hydraulic oil in the hydraulic chamber to the movement of the main positioning column 401. The pre-compression member 16 is located on the right side of the sealing column 13, that is, the pre-compression member 16 and the main positioning column 401 are both located on the same side of the hydraulic chamber. The height of the inclined surface of the wedge block 12 in the direction of the central axis of the sealing column 13 is greater than the diameter of the connecting hole 131. This allows the sealing column 13 to move under the pressure of the wedge block 12, first isolating the hydraulic chamber, and then the sealing column 13 drives the pre-compression member 16 to move, increasing the pressure in the right hydraulic chamber. The dustproof ring 18 is made of elastic rubber, and the part of the dustproof ring 18 located in the guide groove of the lead screw 2 is in a stress-free state, while the part of the dustproof ring 18 in contact with the lead screw 2 is in a compressed state.

[0056] The working principle of the above scheme is as follows: When the lead screw 2 drives the worktable 3 to move to the left, the lead screw 2 drives the main nut 4 and the auxiliary nut 5 to move to the left. The main nut 4 drives the worktable 3 to move to the left, and the main nut 4 and the auxiliary nut 5 together drive the mounting part 6 to move to the left. The lead screw 2 drives the dustproof ring 18 to rotate relative to the mounting ring 11 by friction. As the mounting part 6 moves to the left, the mounting part 6 drives the dustproof ring 18 to move together through the mounting ring 11, so that the dustproof ring 18 and the lead screw 2 slide against each other. At this time, the mounting ring 11 and the dustproof ring 18 remain in the initial position on the mounting part 6. When the lead screw 2 drives the worktable... 3. When moving to the right, as the mounting part 6 moves to the right, the dustproof ring 18 remains stationary under the action of friction between it and the lead screw 2, causing the dustproof ring 18 to drive the mounting ring 11 to move to the left relative to the mounting part 6 (the following explanation will take the parts in the hydraulic chamber above as an example). The mounting ring 11 drives the wedge block 12 to move, and the wedge block 12 squeezes the sealing column 13 upward through the inclined surface (and compresses the air between the upper side of the sealing column 13 and the mounting part 6). The sealing column 13 drives the extrusion plate 17 to move upward, so that the connecting hole 131 gradually misaligns with the hydraulic chamber, and finally the sealing column 13 isolates the hydraulic chamber.

[0057] As the sealing column 13 moves upward, the distance between the extrusion plate 17 and the pre-compression member 16 gradually decreases until they come into contact and push the pre-compression member 16 upward. This reduces the space in the right hydraulic chamber and increases the pressure, causing the sealing rings on the main positioning column 401 and the sealing column 13 to deform. Eventually, the mounting ring 11 moves to the leftmost side of the mounting member 6 and stops moving. The dust ring 18 stops moving, and the sealing column 13 loses contact with the inclined surface of the wedge block 12 and contacts the upper side of the wedge block 12. This allows the secondary nut 5 to provide the main nut 4 with a rightward thrust through the mounting member 6, the hydraulic oil in the right part of the hydraulic chamber, the sealing ring on the main positioning column 401, and the main positioning column 401, thereby reducing the compressive force on the elastic member 10 and reducing the probability of deformation of the elastic member 10.

[0058] When the worktable 3 is moved to the left again by the lead screw 2, the lead screw 2 drives the dustproof ring 18 to move to the right and reset through friction. The dustproof ring 18 drives the mounting ring 11 to move to the right relative to the mounting part 6. The above steps are repeated in reverse so that the wedge block 12, the sealing column 13, the pre-compression part 16 and the extrusion plate 17 are reset together.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A lead screw transmission device for CNC machine tools, characterized in that, include: The operating table (1) is rotatably connected to a lead screw (2), and the operating table (1) is slidably connected to a worktable (3), and the worktable (3) is provided with an extension hole (301). The main nut (4) is threaded to the lead screw (2) and fixed to the worktable (3). The lead screw (2) is threaded to the auxiliary nut (5). The main nut (4) and the auxiliary nut (5) are respectively fixed to the opposite sides of the main nut (4) and the auxiliary nut (5). Mounting component (6) is slidably connected to the main positioning post (401) and fixedly connected to the secondary positioning post (501). Mounting component (6) is in contact with the secondary nut (5). Mounting component (6) is provided with an adjustment hole (601). The central axis of the adjustment hole (601) is collinear with the central axis of the extension hole (301). An adjustment component, disposed on the mounting part (6), is used to adjust the gap between the main nut (4) and the secondary nut (5) through the extension hole (301); The adjustment component includes: The intermediate component (7) is rotatably connected to the mounting component (6), and an adjusting rod (8) is rotatably connected in the adjusting hole (601). The adjusting rod (8) and the intermediate component (7) form a worm gear structure. The extrusion part (9) is threaded to the mounting part (6) and splined to the transfer part (7); Also includes: Multiple main locating pins (101) are fixed to the side of the extruder (9) near the main nut (4), and multiple secondary locating pins (102) are fixed to the side of the main nut (4) near the extruder (9). A number of elastic elements (10) are disposed between the main nut (4) and the pressing element (9), and are respectively fixed to the adjacent main positioning pin (101) and the adjacent secondary positioning pin (102). The number of elastic elements (10) is not greater than the number of main positioning pins (101), and the number of elastic elements (10) is not greater than the number of secondary positioning pins (102). Also includes: The mounting ring (11) is slidably connected to the mounting component (6). The mounting ring (11) is fixedly connected to a wedge (12). The mounting component (6) is provided with a pressurized flow channel (121) that runs through its central axis. The main positioning column (401) slides and seals within the pressurized flow channel (121). A sealing column (13) is slidably connected to the side of the mounting component (6) near the wedge (12). The wedge (12) is used to squeeze the sealing column (13). The sealing column (13) divides the pressurized flow channel (121) into two parts. The sealing column (13) is provided with a connecting hole (131). The connecting hole (131) is used to connect the pressurized flow channel (121) that is separated by the sealing column (13). The elastic cylinder (14) is fixedly attached to a portion of the pressurized flow channel (121) away from the main positioning post (401); A sealing pin (15) is detachably connected to one end of the pressurized flow channel (121) near the secondary nut (5).

2. A lead screw transmission device for CNC machine tools according to claim 1, characterized in that, The cross-sectional shape of the spline connection between the extrusion member (9) and the transfer member (7) is an isosceles trapezoid, and the width of the isosceles trapezoid gradually increases in the direction that gradually approaches the central axis of the extrusion member (9).

3. A lead screw transmission device for a CNC machine tool according to claim 2, characterized in that, There is a distance between the mounting component (6) and the main nut (4).

4. A lead screw transmission device for a CNC machine tool according to claim 3, characterized in that, The projection of the elastic element (10) onto the end face of the main nut (4) has a central angle less than 180° with the center point of the end face of the main nut (4) as the center.

5. A lead screw transmission device for a CNC machine tool according to claim 4, characterized in that, The mounting component (6) has a pre-compression component (16) that is slidably connected to the side of the sealing post (13). The sealing post (13) is fixedly connected to a compression plate (17), which is used to compress the pre-compression component (16).

6. A lead screw transmission device for a CNC machine tool according to claim 5, characterized in that, The wedge (12) presses the plug (13) to move by means of its inclined surface, and the height of the inclined surface of the wedge (12) in the direction of the central axis of the plug (13) is greater than the diameter of the connecting hole (131).

7. A lead screw transmission device for a CNC machine tool according to claim 6, characterized in that, The mounting ring (11) is rotatably connected to a dustproof ring (18), and the minimum distance between the dustproof ring (18) and the central axis of the lead screw (2) is less than the radius of the lead screw (2).

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