Screw pair installation stress relief device

Abstract

The present invention discloses a device for eliminating stress in installing a screw pair, comprising a self-lubricating connecting block provided between two vertical blocks of a connecting bearing seat; the self-lubricating connecting block has six faces, with a first through hole extending from the bottom face to the top face; a nut connecting seat has a mirror-image protrusion on one end that cooperates with the two sides of the self-lubricating connecting block, with two coaxial bearing holes on the two protrusions, and a nut connecting seat has a second through hole coaxial with its outer ring; the connecting bearing seat has mirror-image vertical blocks that cooperate with the other two sides of the self-lubricating connecting block, with two coaxial bearing holes on the two vertical blocks, with transmission limit sleeves installed in the bearing holes through bearings, the transmission limit sleeves being embedded in the four sides of the self-lubricating connecting block and being locked to the self-lubricating connecting block by screws passing through the limit sleeves; a third through hole is provided at the bottom of the connecting bearing seat; the first through hole, the second through hole, and the third through hole are coaxially arranged for the screw of the screw pair to pass through, and an elastic mechanism is provided in the gap between the nut connecting seat and the connecting bearing seat. The present invention eliminates stress in installing a screw pair.

Description

Technical Field

[0001] The invention relates to the technical field of screw pair installation, in particular to a screw pair installation stress relief device. Background Art

[0002] Under the existing technology, in the mechanical structure driven by the screw pair, the screw pair is usually used in the following way: the two ends of the screw are fixed on the bearing seat, the bearing seat is fixed on the fixed end face of the equipment, the screw nut is fixed on the nut fixing block of the transfer platform, the transfer platform is installed on the slider of the linear slide rail, the slide rail is installed on the slide rail pad, the slide rail pad is fixed on the fixed end face of the equipment, the motor output shaft and the screw lever shaft end are connected through a coupling; the motor drives the screw to rotate, and the screw nut drags the transfer platform to move back and forth in a straight line.

[0003] The debugging method for a single-screw pair structure is: attach the dial indicator to the transfer platform, make the dial indicator measuring head contact the screw, drag the transfer platform along the extension direction of the linear slide, observe the needle swing deviation, adjust the tightening force of the fixing screws of the bearing seat and the screw nut, reduce the friction of the running transmission structure, and improve the smoothness of the screw pair operation. Repeat the above steps until the installation accuracy meets the standard. During the installation and debugging of the screw pair structure, not only the assembly level of the installer is tested, but also the equipment installation end face and related parts are required to have a high degree of processing accuracy. Installation stress is easily generated during assembly, and it is impossible to completely avoid installation stress during the installation process. The debugging method of the double-screw pair structure is similar to it, but more complicated.

[0004] From a tolerance perspective, the cause of installation stress is that the lead screw and lead nut are mounted on different reference surfaces. Machining makes it difficult to eliminate the geometric tolerances between the two reference surfaces, resulting in installation stress. Furthermore, traditional lead screw assembly installation methods over-define the positional accuracy of the lead screw assembly structure, forcing concentricity deviations between the lead screw and lead nut. The resulting tension between the two causes the lead screw to bend and deform, increasing transmission resistance, leading to poor operation of the lead screw assembly, damage to the lead screw nut, and even lead screw breakage.

[0005] The improved technology proposed by patent CN203343806U has improved this type of problem. This patent mainly adopts a wedge-shaped slider structure or a ball head structure connection method to avoid the rigid connection between the screw nut and the transfer structure, prevent the stress and deformation generated during the installation of the screw pair, and eliminate the installation stress of the device. In addition, the fitting clearance between the sliding blocks of the stress relief device of this patent is large and the precision is low; the connection structure has high friction, is prone to jamming, has low load-bearing capacity, and is not compatible, which cannot meet the use requirements of the screw under high-speed transmission conditions.

[0006] Furthermore, under existing technology, traditional screw assembly installation methods are complex and require high-precision machining of equipment components, as well as high-level assembly skills from the equipment assemblers. High machining precision translates to high manufacturing costs; complex installation and commissioning, coupled with low assembly efficiency, further increase manufacturing costs. Therefore, it is necessary to provide a device that can avoid installation stress during installation, reduce equipment installation difficulty and machining costs, reduce maintenance frequency, and extend equipment life. Summary of the Invention

[0007] The purpose of the present invention is to provide a screw pair installation stress relief device that is easy to install and debug, has a reliable structure, strong load capacity, and saves equipment manufacturing costs in order to address the technical defects existing in the prior art.

[0008] The present invention is implemented as follows: a screw pair installation stress relief device includes a nut connecting seat, a connecting bearing seat and a self-lubricating connecting block that plays a connecting role between the nut connecting seat and the bearing connecting seat; the self-lubricating connecting block is arranged between the two oppositely arranged vertical blocks of the connecting bearing seat; the self-lubricating connecting block has six faces, and a first through hole is formed from the bottom surface to the top surface; one end of the nut connecting seat has a protrusion that is a mirror image of each other and cooperates with the two side surfaces of the self-lubricating connecting block, and the nut connecting seat has a second through hole coaxially arranged with its outer ring; the connecting bearing seat has vertical blocks that are a mirror image of each other and cooperate with the two side surfaces of the self-lubricating connecting block, and the two The protrusion and the two vertical blocks each form a bearing hole; a transmission limit sleeve is installed in each bearing hole through a bearing, and the inner end face of each transmission limit sleeve is embedded and installed in the corresponding sleeve holes on the four side surfaces of the self-lubricating connecting block and is locked and fixed to the self-lubricating connecting block by screws passing through the limit sleeve; a third through hole is provided at the bottom of the connecting bearing seat; the first through hole, the second through hole and the third through hole are coaxially arranged for the screw of the screw pair to pass through; an elastic mechanism is installed in the gap between the nut connecting seat and the connecting bearing seat, which is used to prevent disordered deflection of the nut connecting seat and suppress resonance during the transmission process of the screw pair structure.

[0009] The bearing and the transmission limit sleeve form a force and torque transmission structure, thereby avoiding sliding friction between the transmission limit sleeve and the nut connection seat, eliminating installation stress and improving transmission efficiency.

[0010] Among them, the elastic mechanism is a spring; the bearing adopts a deep groove ball bearing, a bearing limit ring is assembled in the bearing hole, and the bearing end cover is respectively tightly fixed to the nut connecting seat and the bearing outer ring connected to the bearing seat; the screw is a hexagon socket flat cup screw.

[0011] The springs are rectangular springs, two in a group, four groups in total, and every two groups are symmetrically arranged relative to the self-lubricating connecting block.

[0012] Among them, a threaded hole is set at the bottom of the connecting bearing seat, and a spring screw plug is installed in the threaded hole. The spring screw plug is used to adjust and control the compression amount of the spring to ensure the balance of the spring force and facilitate the installation of the spring.

[0013] Wherein, the inner surface of the first through hole of the self-lubricating connecting block is inlaid with a plurality of self-lubricating materials for reducing friction resistance between materials.

[0014] Wherein, the self-lubricating material is graphite.

[0015] Wherein, the self-lubricating connecting block is made of tin bronze.

[0016] Wherein, the nut connecting seat and the connecting bearing seat are made of steel and are subjected to modulation and chrome plating.

[0017] The connecting bearing seat is formed by fixing a vertical block and a base plate by welding and then cutting through precision machining.

[0018] The screw pair installation stress elimination device of the present invention suppresses the screw transmission resonance by an elastic mechanism, uses a bearing and a self-lubricating connecting block with a through hole, connects the screw nut connecting seat and the connecting bearing seat through a transmission limit sleeve and screws, avoids the rigid connection between the screw nut and the transfer plate or the connecting block, and eliminates the screw pair installation stress.

[0019] The present invention forms a spherical connection between the lead screw nut and the transfer plate, avoiding excessive definition of the lead screw assembly structure and the slide rail structure during installation, ensuring smooth operation of the transmission structure. The present invention also has the function of transmitting force and torque, overcoming the frictional resistance between the lead screw nut and the lead screw, ensuring that the lead screw nut and the transfer plate are relatively stationary, and realizing effective transmission of the lead screw assembly.

[0020] The screw pair mounting stress relief device of the present invention has a wide range of applications and can be used in automation equipment and machine tool equipment; the installation methods are diversified and can meet the requirements of horizontal installation and vertical installation; the load-bearing capacity is large and the torque is effectively transmitted; the friction coefficient is low and the transmission efficiency is high, which can meet the requirements of use under high-speed and long-distance rotation conditions; and the installation difficulty and equipment manufacturing cost are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the appearance of a stress relief device installed in a screw pair according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the exploded structure of a stress relief device installed in a screw pair according to an embodiment of the present invention.

[0023] Figure 3 Schematic diagram of a lifting device of a screw pair transmission structure using a stress relief device according to an embodiment of the present invention.

[0024] Figure 4 Schematic diagram of the structure of the screw rod pair according to an embodiment of the present invention.

[0025] Figure 5 Schematic diagram of the fixation between the stress relief device and the mounting base according to an embodiment of the present invention.

[0026] Figure 6 Schematic diagram of a translation device of a screw pair transmission structure of a single screw transmission structure using a stress relief device according to an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1. Nut connecting seat, 2. Rectangular spring, 3. Hexagon socket flat cup screw, 4. Transmission limit sleeve, 5. Deep groove ball bearing, 6. Self-lubricating connecting block, 7. Bearing end cover, 8. Connecting bearing seat, 9. Spring plug, 10. Linear slide, 11. Screw pair, 12. Stress relief device, 13. Right-angle gearbox, 14. Bearing seat, 15. Lifting platform frame, 16. Slider mounting plate, 17. Platform large plate, 18. Coupling, 19. Lifting power assembly, 20. Lifting power mounting seat, 21. Screw nut, 22. Screw, 23. Mounting seat, 24. Slide rail support block, 25. Bottom large plate, 26. Servo motor mounting seat, 27. Servo motor, 28. Transfer platform bracket, 29. Transfer small plate, 101. Bearing limit ring. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0030] The screw pair installation stress elimination device of the present invention suppresses the screw transmission resonance by an elastic mechanism, uses a bearing and a self-lubricating connecting block with a through hole, connects the screw nut connecting seat and the connecting bearing seat through a transmission limit sleeve and screws, avoids the rigid connection between the screw nut and the transfer plate or the connecting block, thereby eliminating the screw pair installation stress.

[0031] See also Figure 1 、 Figure 2As shown, a screw pair installation stress relief device comprises a nut connecting seat 1, a transmission limiting sleeve 4, a self-lubricating connecting block 6, and a connecting bearing seat 8; the connecting bearing seat 8 is formed by two vertical blocks fixed to a base plate; the self-lubricating connecting block 6 is preferably a square block with six faces, a first through hole is formed from its bottom surface to the top surface, and a screw hole is formed on each of its four side surfaces; the center of the nut connecting seat 1 has a second through hole arranged coaxially with the outer ring; the inner sides of the two mirror-image protrusions of the nut connecting seat 1 are sleeved and installed on the two outer sides of the self-lubricating connecting block 6; the inner sides of the two mirror-image vertical blocks of the connecting bearing seat 8 are sleeved and installed on the other two outer sides of the self-lubricating connecting block 6; two coaxial bearing holes are formed on the two vertical blocks of the connecting bearing seat 8; and a screw hole is formed on the two protrusions of the nut connecting seat 1 Two other coaxial bearing holes; a bearing is respectively installed in the bearing holes on the two vertical blocks of the connecting bearing seat 8 and the bearing holes on the two protrusions of the nut connecting seat 1, and the inner hole of each bearing is coaxially equipped with a transmission limit sleeve 4; the inner end of the transmission limit sleeve 4 is embedded and installed in the corresponding sleeve holes on the four side surfaces of the self-lubricating connecting block 6, and the four screws for fixing each pass through a transmission limit sleeve and are threadedly connected and fixed with the screw holes on the four side surfaces of the self-lubricating connecting block; a third through hole is provided at the bottom of the connecting bearing seat 8; the first through hole, the second through hole and the third through hole are coaxially arranged for the screw of the screw pair to pass through; an elastic mechanism is installed in the gap between the nut connecting seat and the connecting bearing seat to prevent disordered deflection of the nut connecting seat and suppress the resonance phenomenon during the transmission process of the screw pair structure.

[0032] Among them, the bearing and the transmission limit sleeve 4 form a force and torque transmission structure, which avoids sliding friction between the transmission limit sleeve 4 and the nut connecting seat 1 and the connecting bearing seat 8, eliminates installation stress and improves transmission efficiency.

[0033] In some embodiments, a bearing end cover 7 is provided on the outer side of the protrusion of the nut connecting seat 1 and the vertical plate connected to the bearing seat 8; the bearing end cover 7 is used to fix the outer ring of the bearing, and is provided with a bearing limit ring 101 to limit the bearing. The bearing is preferably a deep groove ball bearing 5, and the bearing can also adopt other types of bearings, such as tapered roller bearings, cylindrical roller bearings, angular contact bearings, etc.

[0034] Among them, the screw is preferably a hexagon socket flat cup screw 3, which passes through the screw countersunk hole in the transmission limit sleeve 4 and is locked and fixed with the screw hole on the self-lubricating connecting block 6; during assembly, the screw is coated with screw glue and then installed to prevent the screw from loosening and falling off.

[0035] In some embodiments, the connecting bearing seat 8 is formed by welding a vertical block to a base plate and then precision machining. A positive tolerance clearance is provided on the inner side of the vertical block to ensure a suitable clearance for the self-lubricating connecting block 6. Furthermore, an assembly clearance is provided between the self-lubricating connecting block 6 and the protrusion of the nut connecting seat 1 to ensure a sliding fit between the protrusion and the self-lubricating connecting block 6.

[0036] In some embodiments, the elastic mechanism is preferably a spring, more preferably a rectangular spring 2; the rectangular spring 2 may also be replaced by other elastic materials, such as black rubber, polyurethane, or other elastic materials. Preferably, in some embodiments, the rectangular springs 2 are arranged in groups of two, for a total of four groups, with each group of two being symmetrically arranged relative to the self-lubricating connecting block 6.

[0037] In some embodiments, a threaded hole for fixing a spring screw plug 9 is provided on the bottom plate of the connecting bearing seat 8 to install the rectangular spring 2. The spring screw plug 9 facilitates the installation of the rectangular spring 2 and the adjustment of the spring compression amount to ensure the balance of the spring force.

[0038] In some embodiments, the inner surface of the first through hole of the self-lubricating connecting block 6 is inlaid with a plurality of self-lubricating materials to reduce friction resistance between the materials. Preferably, the self-lubricating material is graphite.

[0039] In some embodiments, the self-lubricating connecting block 6 is made of tin bronze, which ensures structural strength while further reducing friction resistance between materials and improving the service life of the device.

[0040] When selecting appropriate bearings, refer to the deep groove ball bearing model and parameter comparison table in Table 1. When selecting a bearing, use the static load rating as the lower limit for bearing capacity. The static load rating of a single bearing should be no less than half the weight of the object being transferred. Table 1 lists the relevant parameters for the 69 series bearings for reference only. Other series bearings can be selected as needed during application.

[0041] Table 1 69 series bearing parameters

[0042] model Inner diameter(mm) Outer diameter (mm) Thickness (mm) Rated dynamic load (N) Rated static load (N) 6900ZZ 10 22 6 3350 1250 6901ZZ 12 24 6 3600 1450 6902ZZ 15 28 7 5400 2250 6903ZZ 17 30 7 5750 2550 6904ZZ 20 37 9 7950 3700 6905ZZ 25 42 9 8750 4550

[0043] See Figure 4 As shown, the screw pair of the present invention is equipped with a stress relief device. When in use, the assembled stress relief device 12 is inserted into the screw pair, and the nut connecting seat 1 is fixed to the screw nut 21; the two axial ends of the screw 22 are installed on the bearing seat, and the bearing seat 8 is connected to the transfer plate and fixed.

[0044] Application Example 1

[0045] like Figure 3 and Figure 4 As shown, the lifting device of the double-screw pair transmission structure includes a linear guide 10, a screw pair 11, a stress relief device 12, a right-angle gear box 13, a seat bearing 14, a lifting platform frame 15, a slider mounting plate 16, a platform large plate 17, a coupling 18, a lifting power component 19, a lifting power mounting seat 20, a screw nut 21, and a screw 22; the linear guide 10 is arranged on the side end face of the lifting platform frame 15, and the end face is processed by machine tool precision milling; the lifting power component 19 is fixed to the lifting power mounting seat 20, and the two are arranged on the lifting platform frame 15. On the mounting plate at the bottom of the platform frame 15; the right-angle gearbox 13 and the lifting power assembly 19 are connected through the coupling 18; the seat bearing 14 is set on the side mounting block of the lifting frame 15; the stress relief device 12 and the screw pair 11 are fixed to each other; the two shaft ends of the screw pair 11 pass through the seat bearing 14 and are connected to the right-angle gearbox 13 through the coupling 18; the slider mounting plate 16 is fixed to the platform plate 17, and then fixed to the slider on the linear slide 10; the connecting base plate 8 in the stress relief device 12 is fixed to the platform plate 17.

[0046] During the debugging process, the dial indicator is fixed on the platform plate 17, the dial indicator measuring head is in contact with the screw 22, and the platform plate 17 is dragged up and down. While dragging the platform plate, the screw rotates accordingly, and the dial indicator measuring head is always in contact with the outer surface of the screw. Observe the needle swing deviation and fine-tune the position of the seat bearing 14 until the needle swing deviation meets the installation requirements.

[0047] The lifting device of the screw pair transmission structure of this embodiment involves the use of this type of screw drive mechanism in the fixture transfer and handling equipment of the square lithium-ion battery production line, and is more commonly used in equipment in other industries.

[0048] Insufficient machining accuracy is a factor that causes the screw pair to be difficult to install and debug. In addition, the stress release deformation of the lifting frame 15 after processing and the extrusion and collision deformation during transportation cause the actual size to deviate from the designed size, which is another factor that makes the screw pair difficult to install and debug.

[0049] The application of the stress relief device of the present invention solves the problem of excessive form and position tolerances caused by frame deformation, saves processing costs, reduces the difficulty of debugging the double-screw transmission structure, and increases the service life of the screw.

[0050] Application Example 2

[0051] Single-screw transmission structures are widely used in the mechanical field. Linear modules usually adopt this single-screw transmission structure. It is also used in machine tools and automatic feeding equipment. The stress relief device of the present invention can also be used in this single-screw transmission structure.

[0052] like Figure 5 and Figure 6 As shown, the translation device of the single screw pair transmission structure includes a linear slide 10, a screw pair 11, a stress relief device 12, a seat bearing 14, a coupling 18, a mounting seat 23, a slide rail support block 24, a bottom large plate 25, a servo motor mounting seat 26, a servo motor 27, a transfer platform bracket 28, and a transfer small plate 29; the bottom large plate 25 is installed on the transfer platform bracket 28; the slider support block 24 is fixed to the bottom large plate 25; the linear slide 10 is arranged on the upper end surface of the slider support block 24, and the slider is fixed to the transfer small plate 29; the seat bearing 14 and the servo motor mounting seat 26 are both arranged on the bottom large plate 25; the stress relief device 12 is inserted into the screw pair 11; the screw pair 11 is inserted into the seat bearing 14 and is connected to the servo motor 27 through the coupling 18; the servo motor 27 is locked with the servo motor mounting seat 26; the mounting seat 23 is locked with the stress relief device 12 and fixed to the transfer small plate 29.

[0053] The debugging method is the same as that in the first application example and will not be described again here.

[0054] In single-screw translation devices, precision machining is typically used to prevent installation stress caused by the different mounting datum surfaces between the lead screw nut and the lead screw. This method results in high machining costs. In translation devices with a single-screw transmission structure and a lead screw pair transmission structure, the application of the stress relief device of the present invention reduces machining precision requirements, saves machining costs, and reduces installation difficulty.

[0055] The screw pair installation stress relief device provided by the present invention has a wide range of applications and can be applied to automation equipment and machine tool equipment; it can be used in both high-speed and low-speed rotation conditions and has high versatility; it reduces the difficulty of installing and debugging the screw pair structure; it adopts a modular design and is easy to install and replace; in terms of layout and cost, it reduces the equipment processing accuracy requirements and saves processing costs; it improves installation efficiency and saves installation costs.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. The screw pair is installed with a stress relief device, characterized in that: The nut connecting seat comprises a nut connecting seat, a connecting bearing seat and a self-lubricating connecting block that serves as a connection between the nut connecting seat and the bearing connecting seat; the self-lubricating connecting block is arranged between the two oppositely arranged vertical blocks of the connecting bearing seat; the self-lubricating connecting block has six faces, and a first through hole is formed from the bottom surface to the top surface; one end of the nut connecting seat has a protrusion that is a mirror image of each other and cooperates with the two side surfaces of the self-lubricating connecting block, and the nut connecting seat has a second through hole coaxially arranged with its outer ring; the connecting bearing seat has vertical blocks that are a mirror image of each other and cooperate with the two side surfaces of the self-lubricating connecting block, and the two protrusions are on the two vertical blocks. Each forms a bearing hole; a transmission limit sleeve is installed in each bearing hole through the bearing, and the inner end face of each transmission limit sleeve is embedded and installed in the corresponding sleeve holes on the four sides of the self-lubricating connecting block and is locked and fixed to the self-lubricating connecting block by screws passing through the limit sleeve; a third through hole is provided at the bottom of the connecting bearing seat; the first through hole, the second through hole and the third through hole are coaxially arranged for the screw of the screw pair to pass through; an elastic mechanism is installed in the gap between the nut connecting seat and the connecting bearing seat to prevent disordered deflection of the nut connecting seat and suppress resonance during the transmission process of the screw pair structure.

2. The screw pair mounting stress relief device according to claim 1, characterized in that: The bearing and the transmission limiting sleeve form a force and torque transmission structure, thereby avoiding sliding friction between the transmission limiting sleeve and the nut connecting seat, eliminating installation stress and improving transmission efficiency.

3. The screw pair mounting stress relief device according to claim 1, characterized in that: The elastic mechanism is a spring; the bearing adopts a deep groove ball bearing, a bearing limit ring is assembled in the bearing hole, and the bearing end cover is respectively tightly fixed to the nut connecting seat and the bearing outer ring connected to the bearing seat; the screw is a hexagon socket flat cup screw.

4. The screw pair mounting stress relief device according to claim 3, characterized in that: The springs are rectangular springs, two in a group, four groups in total, and every two groups are symmetrically arranged relative to the self-lubricating connecting block.

5. The screw pair mounting stress relief device according to claim 1, characterized in that: A threaded hole is provided at the bottom of the connecting bearing seat; a spring screw plug is installed in the threaded hole; the spring screw plug is used to adjust and control the compression amount of the spring, ensure the balance of the spring force, and facilitate the installation of the spring.

6. The screw pair mounting stress relief device according to claim 1, characterized in that: The inner surface of the first through hole of the self-lubricating connecting block is inlaid with a plurality of self-lubricating materials for reducing friction resistance between materials.

7. The screw pair mounting stress relief device according to claim 6, characterized in that: The self-lubricating material is graphite.

8. The screw pair mounting stress relief device according to claim 1, characterized in that: The self-lubricating connecting block is made of tin bronze.

9. The screw pair mounting stress relief device according to claim 1, characterized in that: The nut connecting seat and the connecting bearing seat are made of steel, and a chrome-plated layer is formed on the surface after chrome plating treatment.

10. The screw assembly mounting stress relief device according to claim 1, characterized in that: The connecting bearing seat is formed by fixing the vertical block and the bottom plate by welding and then undergoing precision machining and cutting.

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