Overhead crane lifting device and lifting method

Abstract

The invention discloses an overhead crane lifting device and a lifting method. The overhead crane lifting device comprises a driving assembly, comprising a first rotating shaft and a second rotating shaft which are spaced and parallel and rotatable; a retracting assembly, comprising a first wheel arranged on the first rotating shaft, a second wheel arranged on the second rotating shaft, and a transmission belt which is wound around the second wheel at one end and connected to the lifting track at the other end after being wound around the first wheel. When the retracting assembly is driven by the driving assembly, the force of the transmission belt being lifted / lowered by the first wheel is greater than the force of the transmission belt being wound / released by the second wheel. The invention effectively improves the stability and reliability of the lifting track and the overhead crane.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor processing, and in particular to an overhead crane lifting device and a lifting method. Background Art

[0002] The automatic material handling system (AMHS), also known as the overhead crane system, is widely used in semiconductor wafer factories. It can accurately and quickly transport wafer boxes to destinations such as process machines. AMHS mainly includes tracks, overhead cranes (OHTs) and control systems. Among them, the tracks include fixed tracks and lifting tracks. The fixed tracks are usually fixed in mid-air, and the lifting tracks can be lifted and lowered under the action of the lifting mechanism. When the lifting track is lifted to the same height as the fixed track, the overhead crane can move from the fixed track to the lifting track or from the lifting track to the fixed track. In the process of the lifting mechanism driving the lifting track to rise and fall, how to smoothly and reliably lift the lifting track and the overhead crane is an urgent problem to be solved. Summary of the invention

[0003] In order to overcome the above-mentioned shortcomings, the purpose of the present invention is to provide an overhead travelling crane lifting device and a lifting method, which effectively improve the stability and reliability of the lifting track and the overhead travelling crane.

[0004] An overhead crane lifting device according to an embodiment of the present invention includes:

[0005] The driving assembly comprises a first rotating shaft and a second rotating shaft which are spaced apart and parallel and rotatable;

[0006] The retractable assembly comprises a first wheel arranged on the first rotating shaft, a second wheel arranged on the second rotating shaft, and a transmission belt with one end wound around the second wheel and the other end connected to the lifting track after being wound around the first wheel. When the retractable assembly is driven by the driving assembly, the force applied to the transmission belt when it is lifted / lowered by the first wheel is greater than the force applied to the transmission belt when it is wound / released by the second wheel.

[0007] Further, there are multiple retractable components, including two first retractable components and two second retractable components, the lifting track includes a first track and a second track that are spaced apart and parallel to each other, the transmission belts of the two first retractable components are respectively connected to the two ends of the first track, and the transmission belts of the two groups of second retractable components are respectively connected to the two ends of the second track; and the transmission belts on the two first wheels located at the same end of the first track and the second track are restricted to the corresponding first wheels through a third wheel.

[0008] Furthermore, it also includes a limit assembly, which includes a connecting block, a connecting shaft, an adjusting shaft, a first locking piece, and a second locking piece; one end of the connecting block is provided with the connecting shaft that can move left and right in the left-right direction, and the other end is provided with the adjusting shaft that can move up and down in the up and down direction; the connecting shaft is locked to the connecting block by the first locking piece, and the third wheels corresponding to the first retractable assembly and the second retractable assembly are respectively installed at both ends of the connecting shaft; the adjusting shaft is hoisted and fixed, and can be locked to the connecting block under the action of the second locking piece.

[0009] Further, the connecting block includes a connecting block body, one end of which is provided with a first narrow slot running through it in the left-right direction, and the other end of which is provided with a second narrow slot running through it in the up-down direction; the bottom of the first narrow slot is connected to a first contoured slot for the connecting shaft to pass through, and the bottom of the second narrow slot is connected to a second contoured slot for the adjusting shaft to pass through.

[0010] Furthermore, one end of the transmission belt away from the second wheel is connected to the lifting track through an adjusting component, and the adjusting component includes a track connecting plate, an adjusting plate, a pressure plate, and an adjusting piece; the adjusting plate and the pressure plate are assembled to form a pressing groove for fixing the transmission belt; the track connecting plate is fixedly connected to the lifting track and can move up and down along the adjusting plate under the action of the adjusting piece.

[0011] Specifically, the adjusting member includes a top plate, an adjusting screw, and an adjusting nut. The top plate abuts against the track connecting plate. The adjusting screw is sequentially arranged on the top plate, the adjusting nut, and the adjusting plate from bottom to top. The adjusting plate is provided with a threaded hole for the adjusting screw to be threadedly connected. Specifically, the driving assembly also includes a first driving member for driving the first rotating shaft and a second driving member for driving the second rotating shaft. The first driving member is a worm gear reduction motor, and the second driving member is a torque motor.

[0012] Furthermore, the retracting and extending assembly also includes a limiting wheel group, which includes a fourth wheel and a fifth wheel, and the fourth wheel and the fifth wheel are both located on the side of the first wheel away from the second wheel; and the transmission belt passes around the fourth wheel, the first wheel, and the fifth wheel in sequence and then is wound around the second wheel.

[0013] The present invention also provides an overhead crane lifting method, which is applied to any of the above-mentioned overhead crane lifting devices; during the lifting process of the lifting track, the linear velocity of the first wheel and the angular velocity of the second wheel are respectively set, and the linear velocity of the first wheel is constant, and the angular velocity of the second wheel decreases step by step;

[0014] During the descent of the lifting track, the linear velocity of the first wheel and the angular velocity of the second wheel are set respectively, and the linear velocity of the first wheel is kept constant while the angular velocity of the second wheel increases step by step.

[0015] Furthermore, the step of setting the angular velocity of the second wheel includes:

[0016] Divide the total stroke of lifting or lowering the transmission belt into a plurality of segmented strokes; set the angular velocity of the second wheel in each segmented stroke to be constant;

[0017] Determining the linear speed of the first wheel when the transmission belt is lifted or lowered based on the total stroke and total time of the lifting or lowering;

[0018] Determining the time corresponding to each of the segmented strokes based on each of the segmented strokes and the linear speed of the first wheel;

[0019] Based on each of the segmented strokes, determining the number of turns of the second wheel winding or releasing;

[0020] The angular velocity of the second wheel is determined based on the number of turns of the second wheel being wound or released and the time corresponding to each of the segmented strokes. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the overhead crane lifting device according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of a driving assembly and a retractable assembly according to an embodiment of the present invention;

[0023] Figure 3 A top view of a driving assembly and a retractable assembly according to an embodiment of the present invention;

[0024] Figure 4 For Figure 3 A schematic diagram of the first retractable assembly being cut along the AA direction;

[0025] Figure 5 for Figure 3 A schematic diagram of the second retractable assembly being cut along the BB direction;

[0026] Figure 6 It is a schematic diagram of the structure of the limit assembly according to an embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of the structure in which the transmission belt is fixed on the second wheel according to an embodiment of the present invention;

[0028] Figure 8 It is a structural schematic diagram of an adjustment component according to an embodiment of the present invention;

[0029] Fig. 9An exploded view of an adjustment assembly according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0031] Example

[0032] In the prior art, the lifting track usually includes two straight rails arranged in parallel. The lifting mechanism includes a lifting drive and four belt retracting assemblies. The belt retracting assemblies include a winding wheel, a guide wheel and a belt. One end of the belt is connected to the lifting track, and the other end is wound on the winding wheel after passing through the guide wheel. The belts of the four belt retracting assemblies are respectively connected to the two ends of the two straight rails of the lifting track. The winding wheels of the four belt retracting assemblies can rotate synchronously under the action of the lifting drive to achieve the synchronous lifting and winding or release and lowering of the four belts, thereby driving the lifting or lowering of the lifting track.

[0033] During the lifting process of the lifting rail, the belt pulling and winding are achieved by driving the winding wheel to rotate through the lifting drive. During the winding process, the diameter of the belt after the winding wheel is wound will become larger and larger, which will cause the linear speed of the belt lifting to become faster and faster, affecting the lifting stability of the lifting rail and the overhead crane. At the same time, since the diameter of the belt after the winding wheel is wound changes gradually, it is difficult to control the lifting height of the lifting rail through the lifting drive, which makes it difficult to accurately dock the lifting rail with the fixed rail.

[0034] Based on this, see Appendix Figure 1-4 As shown, a crane lifting device of the present invention includes a driving assembly and a retracting assembly. The driving assembly includes a first rotating shaft 11 and a second rotating shaft 12 which are spaced apart and parallel and rotatable. The first rotating shaft 11 is driven by a first driving member 13, and the second rotating shaft 12 is driven by a second driving member 14. The retracting assembly includes a transmission belt 21 and a first wheel 22 and a second wheel 23 which are sequentially arranged in the front-back direction. The first wheel 22 is mounted on the first rotating shaft 11 to lift or lower the transmission belt 21; the second wheel 23 is mounted on the second rotating shaft 12 to reel in or release the transmission belt 21, and one end of the transmission belt 21 is fixedly wound on the second wheel 23, and the other end is connected to the lifting track 3 after passing the first wheel 22.

[0035] The retracting and releasing assembly can be driven by the driving assembly to realize the lifting and lowering of the lifting track 3. When the lifting track 3 is lifted, the first rotating shaft 11 is driven to rotate by the first driving member 13 (such as an electric motor or a hydraulic motor), and the first wheel 22 installed on the first rotating shaft 11 rotates immediately and pulls the transmission belt 21 up; at the same time, the second rotating shaft 12 is driven to rotate by the second driving member 14 (such as an electric motor or a hydraulic motor), and the second wheel 23 installed on the second rotating shaft 12 rotates immediately, and the second wheel 23 immediately reels the transmission belt 21 pulled up by the first wheel 22. At this time, the force of the transmission belt 21 being lifted by the first wheel 22 and rising is greater than the force of the transmission belt 21 being reeled by the second wheel 23. When the lifting track 3 is lowered, the second driving member 14 drives the second wheel 23 to rotate through the second rotating shaft 12, and the transmission belt 21 wound on the second wheel 23 is gradually released. At the same time, the first driving member 13 drives the first wheel 22 to rotate through the first rotating shaft 11, and the first wheel 22 lowers the transmission belt 21 released by the second wheel 23. At this time, the force exerted on the transmission belt 21 by the first wheel 22 is greater than the force exerted on the transmission belt 21 by the second wheel 23.

[0036] Compared with the prior art, the first wheel 22 and the second wheel 23 are driven to rotate respectively by the driving components, and the lifting and lowering actions and the winding / releasing actions of the transmission belt 21 are performed separately, wherein the first driving member 13 and the first wheel 22 only pull or lower (i.e., lift) the transmission belt 21, and the wound transmission belt 21 will not be retained on the first wheel 22. Therefore, the diameter of the first wheel 22 will not change. At this time, the lifting or lowering stroke of the transmission belt 21 can be accurately controlled by controlling the driving accuracy of the first driving member 13, thereby facilitating accurate control of the docking position of the lifting track 3 and the fixed track; and the second driving member 14 and the second wheel 23 wind up the transmission belt 21 pulled up by the first wheel 22 or release the transmission belt 21 to meet the demand of the first wheel 22 to lift or lower the transmission belt.

[0037] The lifting action of the first wheel 22 on the transmission belt 21 directly acts on the lifting track 3. Since the diameter of the first wheel 22 remains unchanged during the driving process, when the first wheel 22 is driven to rotate at a constant speed, the lifting speed of the transmission belt 21 is constant, thereby ensuring that the lifting track 3 is lifted and lowered smoothly at a constant speed. When multiple sets of retractable components are used, due to the independent driving of the first wheel 22 and the second wheel 23, the winding tightness of the multiple sets of second wheels 23 will not interfere with the lifting action of the first wheel 22 on the transmission belt 21, thereby avoiding the skew phenomenon of the lifting track caused by the inconsistent tightness of multiple sets of transmission belts in the prior art, while improving the lifting stability of the lifting track, avoiding the problem of being unable to dock with the fixed track due to the skew of the lifting track.

[0038] In addition, compared with the single driving member in the prior art that takes into account both the lifting and winding functions, the cooperation between the first driving member 13 and the second driving member 14 can effectively reduce the load of the single driving member and avoid the problem of unstable installation caused by excessive local force at the installation point during installation.

[0039] In order to improve the stability of the lifting track 3, in some embodiments, there are multiple retractable components, including two first retractable components and two second retractable components, and the lifting track 3 includes a first track and a second track that are spaced and parallel, and the transmission belts 21 of the two groups of first retractable components are respectively connected to the two ends of the first track, and the transmission belts 21 of the two groups of second retractable components are respectively connected to the two ends of the second track. The arrangement of four groups of retractable components can provide connection points for the lifting track 3 from four positions, thereby improving the lifting stability of the lifting track 3. The number of retractable components is not limited to four groups. When the number of retractable components is more, the number of connection points to the lifting track 3 is more, and the force on each retractable component is smaller; correspondingly, when the number of retractable components is smaller, the force on each retractable component is greater.

[0040] Taking the arrangement of four groups of retractable assemblies as an example, since the first wheels 22 of the two groups of first retractable assemblies and the two groups of second retractable assemblies are both mounted on the first rotating shaft 11, the second wheels 23 of the two groups of first retractable assemblies and the two groups of second retractable assemblies are both mounted on the second rotating shaft 12. The first driving member 13 can simultaneously drive the transmission belts 21 of the two groups of first retractable assemblies and the two groups of second retractable assemblies to be synchronously pulled up or lowered through the first rotating shaft 11, and similarly, the second driving member 14 can simultaneously drive the transmission belts 21 of the two groups of first retractable assemblies and the two groups of second retractable assemblies to be synchronously wound up or released through the second rotating shaft 12.

[0041] Since the first wheels 22 of the four retractable assemblies are all installed on the first rotating shaft 11, the rotation speeds of the four first wheels 22 remain the same, thereby ensuring that the lifting or lowering lengths of the four transmission belts 21 are the same, ensuring that the lifting track 3 can be lifted and lowered smoothly.

[0042] In addition, since the four groups of retractable components all use the first driving member 13 and the second driving member 14 to realize independent retractable and unreeling actions and lifting actions, the lifting actions of the four groups of retractable components are not affected by the reeling and releasing actions, thereby effectively avoiding the inconsistency of the lifting heights of the multiple groups of transmission belts 21 caused by the difference in the tightness of the reeling and releasing of the multiple groups of transmission belts 21 in the prior art, thereby ensuring the stability of the lifting track 3 and the overhead crane lifting.

[0043] Since the side of the first wheel 22 facing the second wheel 23 may have a risk of partial tooth disengagement of the transmission belt 21 (teeth on the transmission belt are not engaged with the first wheel). Figure 4-5As shown, the transmission belt 21 can be restricted on the first wheel 22 by the third wheel 4. The third wheel 4 is located between the first wheel 22 and the second wheel 23, and the third wheel 4 can restrict the transmission belt 21 on the first wheel 22 to ensure that the first wheel 22 and the transmission belt 21 are fully engaged. When the transmission belt 21 on the first wheel 22 tends to be separated from the first wheel 22, or the transmission belt 21 tends to be deflected on the first wheel 22, the third wheel 4 can restrict the transmission belt 21 on the first wheel 22 by pressing or abutting, so as to inhibit the transmission belt 21 from being separated from the first wheel 22, and ensure that the transmission belt 21 and the first wheel 22 are always in an engaged state.

[0044] In some embodiments, see Appendix Figure 3 As shown, the transmission belt 21 located at the same end of the first track and the second track and passing through the first wheel 22 can be limited by two third wheels 4 on the same axis. In this way, the consistency of the pressing height of the two third wheels 4 can be ensured, thereby avoiding the situation where the transmission belts 21 of the first retractable assembly and the second retractable assembly located at the same end of the first track and the second track are one loose and the other tight.

[0045] In some embodiments, the overhead crane lifting device further includes a limit assembly 5, see the attached Figure 6 As shown, the limit assembly 5 includes a connecting block 51, a connecting shaft 52, an adjusting shaft 53, a first locking member 54, and a second locking member 55, wherein the connecting block 51 is located between the first retractable assembly and the second retractable assembly, and one end of the connecting block 51 is provided with a connecting shaft 52 that can move left and right along the left-right direction, and the other end of the connecting block 51 is provided with an adjusting shaft 53 that can move up and down along the vertical direction. The connecting shaft 52 is locked on the connecting block 51 by the first locking member 54, and the third wheels 4 corresponding to the first retractable assembly and the second retractable assembly are respectively installed at both ends of the connecting block 51. The upper end of the adjusting shaft 53 is hoisted and fixed by the mounting seat 56, and the lower end can be locked on the connecting block 51 under the action of the second locking member 55.

[0046] By moving the connecting shaft 52 left and right, the positions of the two third wheels 4 can be adjusted to ensure that the two third wheels 4 can be aligned with the first wheels 22 of the first and second retractable assemblies respectively; by moving the adjusting shaft 53 up and down, the connecting block 51 and the connecting shaft 52 can be driven to move up and down, thereby driving the two third wheels 4 to move up and down synchronously to adjust the clamping height of the third wheels 4. The first locking member 54 and the second locking member 55 can be set to lock the position of the limit assembly 5 during operation to ensure the stability of the clamping effect.

[0047] In some embodiments, the connecting block 51 includes a connecting block body, one end of which is provided with a first slot running through the left and right directions thereof, and the other end of which is provided with a second slot running through the upper and lower directions thereof. The bottom of the first slot is connected with a first profiling slot for the connecting shaft 52 to pass through, and the bottom of the second slot is connected with a second profiling slot for the adjusting shaft 53 to pass through. The first locking member 54 is a locking bolt that is passed through the first slot in the vertical direction. When the locking bolt of the first locking member 54 is continuously tightened, the slot width of the first slot is continuously reduced so that the connecting shaft 52 is pressed against the first profiling slot. Similarly, the second locking member 55 is a locking bolt that is passed through the second slot in the left and right directions. When the locking bolt of the second locking member 55 is continuously tightened, the slot width of the second slot is continuously reduced so that the adjusting shaft 53 is pressed against the second profiling slot. The quick disassembly and displacement of the connecting shaft 52 and the adjusting shaft 53 is realized by the cooperation of the connecting block 51 with the first locking member 54 and the second locking member 55.

[0048] In some embodiments, see Appendix Figure 1 , Figure 7 As shown, one end of the transmission belt 21 is fixedly pressed on the second wheel 23 through the transmission belt pressing plate 6, and the other end is fixedly connected to the lifting track 3 through the adjustment component 7. Figure 8-9 As shown, the adjustment component 7 includes a track connecting plate 71, an adjustment plate 72, a pressure plate 73, and an adjustment member, wherein the adjustment plate 72 and the pressure plate 73 are assembled to form a pressing groove for fixing the transmission belt 21. The track connecting plate 71 is fixedly connected to the first track or the second track of the lifting track 3, and can move up and down relative to the adjustment plate 72 under the action of the adjustment member. Furthermore, a toothed structure that can mesh with the transmission belt 21 is provided on the side of the pressure groove facing the transmission belt 21. By driving the track connecting plate 71 to move up and down relative to the adjustment plate 72 through the adjustment member, the position of the track connecting plate 71 relative to the adjustment plate 72 can be adjusted, and then the relative position of the transmission belt 21 and the lifting track 3 can be adjusted, so as to facilitate adjusting the lifting track 3 connected to the four sets of retractable components to the horizontal direction.

[0049] Specifically, a threaded hole is opened at the lower end of the adjustment plate 72, and the adjustment member includes a top plate 74, an adjustment screw 75, and an adjustment nut 76. The top plate 74 abuts against the lower end surface of the track connecting plate 71, and the adjustment screw 75 is successively passed through the threaded holes of the top plate 74, the adjustment nut 76, and the adjustment plate 72 from bottom to top.

[0050] When the locking nut 75 is in the locked state, the locking nut 76 is in the locked state, and the locking nut 76 is in the locked state.

[0051] Furthermore, a limiting groove 711 for the adjustment plate 72 to move is provided on the track connection plate 71, and the pressure plate 73 is connected to the adjustment plate 72 by screws.

[0052] Furthermore, in order to prevent the transmission belt 21 from sliding in the pressure groove formed by the adjustment plate 72 and the pressure plate 73, and to improve the transmission stability and transmission accuracy of the transmission belt 21, the transmission belt 21 can adopt a toothed belt, and the first wheel 22 is a toothed belt wheel that meshes with the toothed belt for transmission.

[0053] In order to ensure that the first wheel 22 and the transmission belt 21 are fully meshed and driven, in some embodiments, see the attached Figure 4-5 As shown, the retractable assembly also includes a limiting wheel set arranged near the first wheel 22, and the limiting wheel set includes a fourth wheel 24 and a fifth wheel 25. The fourth wheel 24 and the fifth wheel 25 are both located on the side of the first wheel 22 away from the second wheel 23, and the fourth wheel 24 is located above the fifth wheel 25; and the transmission belt 21 is wound around the fourth wheel 24, the first wheel 22, and the fifth wheel 25 in sequence and then wound on the second wheel 23. Through the cooperation of the fourth wheel 24 and the fifth wheel 25, the travel angle of the transmission belt 21 on the first wheel 22 is larger. When the first wheel 22 drives the transmission belt 21 to transmit, the transmission belt 21 can mesh with more teeth of the first wheel 22, thereby making the alternating force on a single tooth on the transmission belt 21 smaller, and the service life of the transmission belt 21 is longer. Furthermore, the fourth wheel 24 and the fifth wheel 25 are hoisted and fixed by the same bearing seat. The lower end surface of the fourth wheel 24 is lower than the upper end surface of the first wheel 22 , so that when the lower end surface of the fourth wheel 24 is pressed against the transmission belt 21 , a certain tension can be applied to the transmission belt 21 .

[0054] In some embodiments, see Appendix Figure 1As shown, the overhead crane lifting device also includes a mounting plate 8 hoisted on the roof, and the driving assembly and the retracting assembly are both mounted on the mounting plate 8, and the retracting assembly also includes a sixth wheel 26 located in front of the first wheel 22 in the front-to-back direction, the sixth wheel 26 is located directly above the lifting track 3, and the transmission belt 21 can be vertically connected to the lifting track 3 after being guided by the sixth wheel 26.

[0055] Since the first retractable assembly and the second retractable assembly are connected to the first track and the second track of the lifting track 3 respectively, when the sixth wheels 26 of the first retractable assembly and the second retractable assembly are respectively arranged directly above the first track and the second track, since there is a certain distance between the first track and the second track, the distance between the first wheel 22 and the sixth wheel 26 of the first retractable assembly and the distance between the first wheel 22 and the sixth wheel 26 of the second retractable assembly are bound to be different. Assuming that the transmission belt 21 of the first retractable assembly is connected to the first track closer to the second wheel 23, and the transmission belt 21 of the second retractable assembly is connected to the second track farther from the second wheel 23, then the distance between the first wheel 22 and the sixth wheel 26 of the second retractable assembly is greater than the distance between the first wheel 22 and the sixth wheel 26 of the first retractable assembly. Accordingly, the length of the transmission belt 21 wound between the first wheel 22 and the sixth wheel 26 of the second retractable assembly is greater than the length of the transmission belt 21 wound between the first wheel 22 and the sixth wheel 26 of the first retractable assembly. In order to avoid the phenomenon of large sagging due to the self-weight of the longer transmission belt 21, in some embodiments, see the attached Figure 5 As shown, the second retractable assembly further includes a seventh wheel 27 located between the first wheel 22 and the sixth wheel 26, and the transmission belt 21 can be wound around the first wheel 22, the seventh wheel 27 and the sixth wheel 26 in sequence. The seventh wheel 27 can support the transmission belt 21 to avoid interference with the lifting of the overhead travelling crane caused by the weight of the transmission belt 21 between the first wheel 22 and the sixth wheel 26.

[0056] In some embodiments, the first driving member 13 adopts a worm gear reduction motor. Since the worm gear reduction motor has a large reduction ratio and torque, when it acts on the first rotating shaft 11 and the first wheel 22, it can smoothly lift the lifting track 3 with a large load and the overhead travelling vehicle on the lifting track 3. At the same time, the worm gear reduction motor has a self-locking function. If the lifting track 3 suddenly loses power during the lifting process, the transmission belt 21 cannot drive the worm to rotate through the turbine, thereby avoiding the risk of the lifting track 3 suspended in the air and the overhead travelling vehicle on the lifting track 3 falling.

[0057] In actual applications, as the second wheel 23 winds the transmission belt 21 at the speed provided by the second driving member 14, the diameter of the transmission belt 21 wound on the second wheel 23 will become larger and larger, and the linear speed of the second wheel 23 winding the transmission belt 21 may be greater than the linear speed of the first wheel 22 lifting the transmission belt 21, and the transmission belt 21 between the second wheel 23 and the first wheel 22 will be at risk of being torn off, which will also affect the stable lifting of the transmission belt 21 by the first wheel 22. Based on this, in some embodiments, the second driving member 14 uses a torque motor. When lifting the lifting track 3, the initial angular velocity of the first wheel 22 can be set to be the same as the initial angular velocity of the second wheel 23. In the initial state, the linear velocity of the first wheel 22 is also the same as the linear velocity of the second wheel 23. As the second wheel 23 reels the transmission belt 21, the diameter of the transmission belt 21 on the second wheel 23 becomes larger and larger, and the linear velocity of the second wheel 23 tends to be faster than the linear velocity of the first wheel 22. At this time, the transmission belt 21 passes through the second wheel 23 to cause the torque motor driving the second wheel 23 to slip. At this time, the angular velocity of the second wheel 23 when winding is lower than the angular velocity driven by the torque motor. The linear velocity of the second wheel 23 when winding the transmission belt 21 is equal to the linear velocity of the first wheel 22 when lifting the transmission belt 21. In this way, the transmission belt 21 between the second wheel 23 and the first wheel 22 can be prevented from being torn apart due to excessive force during lifting. At the same time, the second wheel 23 will not affect the linear velocity of the first wheel 22 when lifting the transmission belt 21.

[0058] When the lifting track 3 is lowered, the initial angular velocity of the first wheel 22 can be set to be the same as the initial angular velocity of the second wheel 23. In the initial state, the linear velocity of the first wheel 22 is also the same as the linear velocity of the second wheel 23. As the second wheel 23 releases the transmission belt 21, the diameter of the transmission belt 21 on the second wheel 23 becomes smaller and smaller. The linear velocity of the transmission belt 21 released by the second wheel 23 tends to be slower than the linear velocity of the transmission belt 21 when the first wheel 22 is lowered. At this time, the release of the transmission belt 21 to the second wheel 23 forms a pulling force. The pulling force causes the torque motor driving the second wheel 23 to slip, and the angular velocity of the second wheel 23 releasing the transmission belt 21 is faster than the angular velocity of the torque motor. The linear velocity of the second wheel 23 releasing the transmission belt 21 is equal to the linear velocity of the first wheel 22 lowering the transmission belt 21. This can prevent the transmission belt 21 between the second wheel 23 and the first wheel 22 from being torn due to excessive force during descent. At the same time, the second wheel 23 will not affect the linear velocity of the first wheel 22 lowering the transmission belt 21.

[0059] This embodiment also provides a method for lifting an overhead crane, including setting the linear velocity of the first wheel 22 and the angular velocity of the second wheel 23 respectively during the lifting process of the lifting track 3, and making the linear velocity of the first wheel 22 constant, and the angular velocity of the second wheel 23 decreasing in a stepwise manner. When the lifting track 3 is lowered, setting the linear velocity of the first wheel 22 and the angular velocity of the second wheel 23 respectively, and making the linear velocity of the first wheel 22 constant, and the angular velocity of the second wheel 23 increasing in a stepwise manner.

[0060] This arrangement allows the transmission belt 21 between the second wheel 23 and the first wheel 22 to have a certain amount of slack (droop) in each stage of step-by-step decrease or increase, thereby avoiding the dragging of the transmission belt 21 between the second wheel 23 and the first wheel 22. At the same time, the slack allows the driving of the first driving member 13 without having to accurately and continuously increase or decrease the angular velocity of the second wheel 23, thereby reducing the difficulty of controlling the angular velocity of the second wheel 23.

[0061] During the whole process of pulling or lowering the transmission belt 21, the drooping amount of the transmission belt 21 between the second wheel 23 and the first wheel 22 is different in different transmission stages. It is possible that the transmission belt 21 hardly droops at a certain stage, at which time, the transmission belt 21 between the second wheel 23 and the first wheel 22 is likely to be almost dragged, while at another stage, the transmission belt 21 may droop too much and interfere with the normal operation of the retracting and releasing assembly.

[0062] To this end, in some embodiments, the step of setting the angular velocity of the second wheel 23 includes:

[0063] The total lifting or lowering stroke of the transmission belt 21 is divided into a plurality of segmented strokes; the angular velocity of the second wheel 23 in each segmented stroke is set to be constant;

[0064] Determine the linear speed of the first wheel 22 when lifting or lowering the transmission belt 21 based on the total stroke and total time of lifting or lowering;

[0065] Determine the time corresponding to each segmented stroke based on each segmented stroke and the linear speed of the first wheel 22;

[0066] Based on each segmented stroke, the number of turns of the second wheel 23 to be wound or released is determined;

[0067] The angular velocity of the second wheel 23 is determined based on the number of turns of the second wheel 23 being wound or released and the time corresponding to each segment stroke.

[0068] In this way, the angular velocity of the second wheel 23 that needs to be controlled in each segment stroke can be calculated and set.

[0069] Since the angular velocity of the second wheel 23 corresponding to each segmented stroke is constant and not continuously changing, it is convenient to control the second driving member 14. Since the total stroke is divided into a plurality of segmented strokes, and the angular velocity of the second wheel 23 is set by the number of turns determined by the segmented strokes, and the time corresponding to each segmented stroke is determined based on each segmented stroke and the speed of the first wheel 22, the transmission belt between the first wheel 22 and the second wheel 23 is allowed to have almost no droop at the end of each segmented stroke, and the drooping transmission belt 21 can be controlled within a smaller range during each segmented stroke, thereby avoiding a large drooping amount of the transmission belt 21 and interfering with the normal operation of the retracting and releasing assembly.

[0070] In practical applications, the length of the segmented stroke can be quantified by the length of each circle of the second wheel 23 winding the transmission belt 21. For example, assuming that the diameter of the second wheel 23 is 50 mm and the thickness of the transmission belt 21 is 3.35 mm. The total stroke of the transmission belt 21 being pulled up or lowered is about 2800 mm. The corresponding relationship between the number of revolutions of the second wheel 23 and the winding length of the transmission belt 21 is analyzed as shown in Table 1.

[0071] Table 1 Correspondence between the number of rotations of the second wheel and the winding length of the transmission belt

[0072]

[0073] Usually, the transmission belt wound during the 1st to 2nd turns of the second wheel is fixed on the second wheel. These two turns of the transmission belt are tightened when being wound and will not participate in the lifting or lowering process of the transmission belt. Therefore, in this example, the length of the wound transmission belt is included in the total lifting or lowering stroke starting from the 3rd turn, that is, the total length of the transmission belt wound from the 3rd to the 12th turns is the total lifting stroke of the transmission belt after the second wheel rotates 12 times.

[0074] When determining the angular velocity of the second wheel, the following steps can be used: the total length of the transmission belt wound from the 3rd to the 6th turns of the second wheel (922.532 mm) is used as the first segmented stroke, the total length of the transmission belt wound from the 7th to the 9th turns of the second wheel (912.798 mm) is used as the second segmented stroke, and the total length of the transmission belt wound from the 10th to the 12th turns of the second wheel (1102.14 mm) is used as the third segmented stroke. Then, a constant angular velocity of the second wheel is set for the first segmented stroke, the second segmented stroke, and the third segmented stroke, respectively. And the angular velocity of the second wheel in the first segmented stroke, the second segmented stroke and the third segmented stroke decreases successively; based on the total lifting time and the total stroke, the linear velocity of the first wheel during lifting is determined, and the linear velocity of the first wheel can be 30mm / s; at this time, the time corresponding to the first segmented stroke, the second segmented stroke and the third segmented stroke can be determined as: 30.75s, 30.43s and 36.738s; based on the first segmented stroke, the second segmented stroke and the third segmented stroke, the number of revolutions of the second wheel corresponding to each segmented stroke can be determined: 4 revolutions, 3 revolutions and 3 revolutions; based on the number of revolutions of the second wheel winding or releasing and the time corresponding to each segmented stroke, the angular velocity of the second wheel rotation is determined: 780.46r / min, 591.59r / min and 489.96r / min.

[0075] At the end of each segmented stroke, the length of the transmission belt lifted by the first wheel is equal to the length of the transmission belt wound by the second wheel, and the transmission belt between the first wheel and the second wheel basically does not sag, and the sagging of the transmission belt can be controlled within a small range during each segmented stroke. Therefore, while avoiding the risk of dragging, the belt sags relatively evenly in each stage of the segmented stroke, avoiding excessive belt sag that interferes with the normal operation of the retracting and releasing components.

[0076] The steps performed by the lifting rail when it is descending can refer to the steps performed by the lifting rail when it is lifted, and will not be repeated here.

[0077] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for lifting a crane applied to a crane lifting device, characterized in that: The overhead crane lifting device comprises: The driving assembly comprises a first rotating shaft and a second rotating shaft which are spaced apart and parallel and rotatable; The retractable assembly comprises a first wheel arranged on the first rotating shaft, a second wheel arranged on the second rotating shaft, and a transmission belt with one end wound around the second wheel and the other end wound around the first wheel and connected to the lifting track, wherein when the retractable assembly is driven by the driving assembly, the force of the transmission belt lifted / lowered by the first wheel is greater than the force of the transmission belt wound / released by the second wheel; The method for lifting the overhead crane comprises: during the lifting process of the lifting track, respectively setting the linear velocity of the first wheel and the angular velocity of the second wheel, and making the linear velocity of the first wheel constant and the angular velocity of the second wheel decreasing step by step; During the descent of the lifting track, the linear velocity of the first wheel and the angular velocity of the second wheel are set respectively, and the linear velocity of the first wheel is kept constant while the angular velocity of the second wheel increases step by step; so that the transmission belt between the second wheel and the first wheel has a droop in each stage of the step-by-step decrease or increase.

2. The method for lifting an overhead crane according to claim 1, characterized in that: There are multiple retractable assemblies, including two first retractable assemblies and two second retractable assemblies. The lifting track includes a first track and a second track that are spaced apart and parallel to each other. The transmission belts of the two first retractable assemblies are respectively connected to the two ends of the first track, and the transmission belts of the two groups of second retractable assemblies are respectively connected to the two ends of the second track; and the transmission belts on the two first wheels located at the same end of the first track and the second track are restricted on the corresponding first wheels through a third wheel.

3. The method for lifting an overhead crane according to claim 2, characterized in that: It also includes a limit assembly, which includes a connecting block, a connecting shaft, an adjusting shaft, a first locking piece, and a second locking piece; one end of the connecting block is provided with the connecting shaft that can move left and right along the left-right direction, and the other end is provided with the adjusting shaft that can move up and down along the up-down direction; the connecting shaft is locked on the connecting block by the first locking piece, and the third wheels corresponding to the first retractable assembly and the second retractable assembly are respectively installed on both ends of the connecting shaft; the adjusting shaft is hoisted and fixed, and can be locked on the connecting block under the action of the second locking piece.

4. The method for lifting an overhead crane according to claim 3, characterized in that: The connecting block includes a connecting block body, one end of which is provided with a first narrow slot running through it in the left-right direction, and the other end of which is provided with a second narrow slot running through it in the up-down direction; the bottom of the first narrow slot is connected to a first contoured slot for the connecting shaft to pass through, and the bottom of the second narrow slot is connected to a second contoured slot for the adjusting shaft to pass through.

5. The method for lifting an overhead crane according to claim 1, characterized in that: One end of the transmission belt away from the second wheel is connected to the lifting track through an adjusting assembly, and the adjusting assembly includes a track connecting plate, an adjusting plate, a pressing plate, and an adjusting member; the adjusting plate and the pressing plate are assembled to form a pressing groove for fixing the transmission belt; the track connecting plate is fixedly connected to the lifting track and can move up and down along the adjusting plate under the action of the adjusting member.

6. The method for lifting an overhead crane according to claim 5, characterized in that: The adjusting member comprises a top plate, an adjusting screw and an adjusting nut. The top plate abuts against the track connecting plate. The adjusting screw is sequentially passed through the top plate, the adjusting nut and the adjusting plate from bottom to top. A threaded hole for threaded connection of the adjusting screw is provided on the adjusting plate.

7. The method for lifting an overhead crane according to claim 1, characterized in that: The driving assembly further includes a first driving member for driving the first rotating shaft and a second driving member for driving the second rotating shaft, wherein the second driving member is a torque motor.

8. The method for lifting an overhead crane according to claim 1, characterized in that: The retracting and extending assembly also includes a limiting wheel group, which includes a fourth wheel and a fifth wheel, and the fourth wheel and the fifth wheel are both located on the side of the first wheel away from the second wheel; and the transmission belt successively passes around the fourth wheel, the first wheel, and the fifth wheel and then is wound around the second wheel.

9. The method for lifting an overhead crane according to claim 1, characterized in that: The step of setting the angular velocity of the second wheel comprises: Divide the total stroke of lifting or lowering the transmission belt into a plurality of segmented strokes; set the angular velocity of the second wheel in each segmented stroke to be constant; Determining the linear speed of the first wheel when the transmission belt is lifted or lowered based on the total stroke and total time of the lifting or lowering; Determining the time corresponding to each of the segmented strokes based on each of the segmented strokes and the linear speed of the first wheel; Based on each of the segmented strokes, determining the number of turns of the second wheel winding or releasing; The angular velocity of the second wheel is determined based on the number of turns of the second wheel being wound or released and the time corresponding to each of the segmented strokes.

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