Safety electric hoist and its transmission mechanism

Abstract

The application relates to a transmission mechanism which comprises an abutting piece, a transmission gear, a mandrel with splines, a pressing sheet and an abutting plate, the splines on the mandrel pass through the inner ring of the transmission gear, the mandrel and the pressing sheet are connected with the splines on the mandrel, the pressing sheet is sleeved on the mandrel, the abutting plate is located on one side of the transmission gear, the pressing sheet is located on the side of the abutting plate away from the transmission gear, the two side surfaces of the transmission gear towards the pressing sheet are respectively fixed with friction sheets, and the abutting piece is used for adjusting the position of the pressing sheet on the mandrel and making the pressing sheet abut against the abutting plate. When the goods hoisted on the output shaft are less than the rated load, the transmission gear and the abutting plate can synchronously move under the action of the friction force of the friction sheets, the hoisting of the goods is realized, when the goods hoisted on the output shaft exceed the rated load, the transmission gear and the abutting plate slip, the goods cannot be hoisted, and the electric hoist can prevent the hoisting of the goods exceeding the rated load.

Description

Safety electric hoist and its transmission mechanism Technical Field

[0001] This application relates to the field of electric hoists, and in particular to a safety electric hoist and its transmission mechanism. Background Technology

[0002] An electric hoist is a special lifting device that is installed on overhead cranes and gantry cranes. Electric hoists are characterized by their small size, light weight, simple operation, and convenient use. They are used in industrial and mining enterprises, warehouses, docks, and other places.

[0003] The invention patent with announcement number CN113879976A discloses a highly stable and safe electric hoist, including an electric hoist body. Two lifting cables connected to a lifting motor are located below the electric hoist body. An auxiliary stabilizing device is also included, comprising two driving components and two abutting rods. A mounting base is located below the electric hoist body. The two lifting cables are respectively threaded through and movably connected to the mounting base. One end of each abutting rod is slidably connected to the mounting base, and the other end of each abutting rod is located below the mounting base and facing the corresponding lifting cable. The end of the abutting rod away from the mounting base is located between the two lifting cables. When the lifting cables sway to one side, the driving component drives the corresponding abutting rod to move away from the swaying side of the lifting cable and abut against the lifting cable.

[0004] The aforementioned technical solutions have the following drawbacks: electric hoists are specified to have a rated load. If an electric hoist lifts goods exceeding its rated load weight, it will damage the hook and lifting cable. The aforementioned electric hoists can only be judged by human judgment of the lifting weight. If operators violate regulations and use them to lift heavy objects exceeding the rated load for extended periods, many safety problems will arise. Summary of the Invention

[0005] To prevent electric hoists from lifting goods exceeding their rated load, this application provides a safety-type electric hoist and its transmission mechanism.

[0006] The transmission mechanism provided in this application adopts the following technical solution:

[0007] A transmission mechanism includes an abutment member, a transmission gear, a splined mandrel, a pressure plate, and an abutment plate. The spline on the mandrel passes through the inner ring of the transmission gear. The mandrel is splinedly connected to the abutment plate. The pressure plate is sleeved on the mandrel. The abutment plate is located on one side of the transmission gear, and the pressure plate is located on the side of the abutment plate away from the transmission gear. A friction plate is fixed to either the side of the transmission gear facing the pressure plate or the side of the abutment plate facing the transmission gear. The abutment member is used to adjust the position of the pressure plate on the mandrel and press the pressure plate against the abutment plate. The abutment plate presses against the friction plate. The mandrel drives the output shaft of a lifting device. The transmission gear is rotatably connected within the lifting device and driven to rotate by the lifting device's drive source. When the load on the output shaft exceeds the rated load, the transmission gear slips against the abutment plate.

[0008] By adopting the above technical solution, when the load on the output shaft is less than the rated load, the transmission gear and the abutment plate can move synchronously under the friction of the friction plate. When the drive source drives the transmission gear to rotate, the transmission gear drives the abutment plate to rotate synchronously. The synchronous belt drives the spline-connected spindle to rotate, and finally drives the output shaft to rotate through the spindle, thus realizing the lifting of the load. When the load on the output shaft exceeds the rated load, the transmission gear and the abutment plate slip, and the drive source cannot drive the spindle to rotate through the transmission gear, thus failing to lift the load. This can prevent the electric hoist from lifting loads exceeding the rated load.

[0009] This application also provides a safety-type electric hoist, which adopts the following technical solution:

[0010] Preferably, the hoist includes a rotation limiter, a hoist body, an output shaft, a hook, and a wire rope. The output shaft and the spindle are both rotatably connected to the hoist body. A main gear is coaxially fixed on the spindle, and a secondary gear is coaxially fixed on the output shaft. The main gear is meshed with the secondary gear. One end of the wire rope is wound around the output shaft, and the other end is fixed to the hook. When the rotation speed of the output shaft exceeds the normal value, the rotation limiter is used to restrict the rotation of the output shaft.

[0011] By adopting the above technical solution, if the operator violates regulations after the goods are lifted and increases the weight of the goods without authorization, making the weight of the goods exceed the rated load, it may cause the transmission gear and the abutment plate to slip, the output shaft to lose its rotation restriction, and the goods to suddenly fall, resulting in a serious accident. At this time, the rotation limiter can restrict the rotation of the output shaft after it loses control, which can promptly limit the fall of the goods and reduce the probability of accidents.

[0012] Preferably, the rotation limiting component includes a driving component, a contact block, a moving rod, and a first gear. The axis of the first gear is perpendicular to the axis of the output shaft. The first gear is rotatably connected to the hoist body along the axis. A rotating ring is coaxially inserted and fixed on the first gear. The moving rod is slidably connected to the hoist body along the axis parallel to the first gear. The moving rod is coaxially inserted and threadedly connected to the rotating ring. The contact block is fixed at the end of the moving rod facing the output shaft. The driving component drives the first gear to rotate. The contact block is used to abut against the output shaft to limit the rotation of the output shaft.

[0013] By adopting the above technical solution, the driving component drives the first gear to rotate, the rotation of the first gear drives the rotating ring to rotate, and the rotation of the rotating ring drives the moving rod threaded on the rotating ring to slide on the hoist body. When the abutting block is away from the output shaft, the abutting block does not affect the rotation of the output shaft. When the abutting block moves to abut against the output shaft, friction occurs between the abutting block and the output shaft, and the abutting block will drive the output shaft to decelerate, thereby slowing down the falling speed of the goods.

[0014] Preferably, the driving component includes a speed measuring drive, a first bevel gear, a second bevel gear, a second gear, and a movable rod. The second gear is rotatably connected to the hoist body along an axis parallel to the first gear and meshes with the first gear. The movable rod is coaxially inserted and slidably connected to the second gear along an axis parallel to the second gear. The movable rod rotates with the second gear and is connected to the hoist body. The first bevel gear is coaxially fixedly sleeved on the output shaft, and the second bevel gear is coaxially fixedly sleeved on the movable rod. The speed measuring drive is used to measure the rotational speed of the output shaft and drive the movable rod to slide on the second gear. When the rotational speed of the output shaft exceeds the normal value, the speed measuring drive drives the movable rod to move until the first bevel gear meshes with the second bevel gear, at which point the abutment block moves toward the output shaft side.

[0015] By adopting the above technical solution, when the rotational speed of the output shaft exceeds the normal value, the speed measuring drive unit drives the movable rod to move to the first bevel gear meshing with the second bevel gear. At this time, the rotation of the output shaft will drive the movable rod to rotate. The rotation of the movable rod will drive the moving rod to move through the cooperation of the first gear and the second gear, thereby causing the abutment block to move towards the output shaft and abut against the output shaft, thus decelerating the output shaft. In the whole process, the force of the output shaft's own rotation is used to control the abutment force of the abutment block on the output shaft. By using the force of the abutment block to stop the force, the rotation of the output shaft is cleverly restricted.

[0016] Preferably, the speed measuring drive component includes a push block, a rotating shaft, a rotating roller, an outer rotating block, and an inner rotating block. The rotating roller is rotatably connected to the hoist body, and the axial direction of the rotating roller is perpendicular to the axial direction of the output shaft. The rotating roller abuts against one of the wire ropes and rotates with the winding and unwinding of the wire rope. The inner rotating block is coaxially fixed on the rotating roller.

[0017] The rotating shaft is rotatably connected to the hoist body. The rotating shaft and the rotating roller are coaxially arranged. The pushing block is slidably connected to the hoist body along the axis parallel to the rotating shaft. One end of the rotating shaft is threaded through and connected to the pushing block. The movable rod is located below the output shaft. The pushing block abuts against the movable rod and is used to push the movable rod to move toward the output shaft.

[0018] The outer rotating block is coaxially fixed on the rotating shaft. A receiving groove is provided on one side of the outer rotating block. The inner rotating block is located in the receiving groove. A first groove is provided on the circumferential outer wall of the inner rotating block. A slider is slidably connected to the first groove along the depth direction of the first groove. A spring is provided on the slider. The two ends of the spring are respectively fixed to the bottom wall of the first groove and the slider. When the output shaft is working normally, the slider is located in the first groove. When the rotation speed of the output shaft exceeds the normal value, the slider moves out of the first groove under the action of centrifugal force and abuts against the circumferential inner wall of the receiving groove. The slider drives the outer rotating block to rotate.

[0019] By adopting the above technical solution, the rotating roller abuts against the wire rope, and the rotating roller can be driven to rotate by the wire rope, thereby indirectly and accurately reflecting the rotation speed of the output shaft at this time. When the cargo is overloaded and falls freely, the rotation speed of the rotating roller exceeds the normal value. The rotating roller drives the inner rotating block to rotate rapidly. Under the action of centrifugal force, the slider moves out of the first groove and abuts against the circumferential inner wall of the receiving groove, thereby driving the outer rotating block to rotate through friction. The rotation of the outer rotating block then drives the rotating shaft to rotate. The rotation of the rotating shaft drives the push block threaded on the rotating shaft to slide on the hoist body, thereby causing the push block to push the movable rod to move. Finally, the first bevel gear and the second bevel gear on the movable rod are meshed, and then the rotation of the output shaft is limited through a series of linkages.

[0020] Preferably, the end of the slider away from the bottom wall of the first groove has an arc-shaped protrusion facing away from the first groove, and a plurality of arc-shaped grooves matching the end of the slider are sequentially opened on the circumferential inner wall of the receiving groove. When the rotational speed of the output shaft exceeds the normal value, the end of the slider is embedded in one of the arc-shaped grooves.

[0021] By adopting the above technical solution, when the rotation speed of the roller exceeds the normal value, the slider moves out of the first groove under the action of centrifugal force. Through the cooperation of the arc-shaped protrusion and the arc-shaped groove, the slider can enter a certain arc-shaped groove, thereby better driving the outer rotating block to rotate.

[0022] Preferably, an extension rod is coaxially rotatably connected to one end of the movable rod near the push block. The extension rod is slidably connected to the hoist body along a direction parallel to the axis of the movable rod. An inclined surface is provided on the bottom surface of the extension rod facing the push block. An arc-shaped block protruding towards the inclined surface is fixed on the push block. The arc-shaped block always abuts against the inclined surface.

[0023] By adopting the above technical solution, the cooperation between the arc-shaped block and the inclined surface enables the movable rod to be pushed better and more smoothly.

[0024] Preferably, a torsion spring is installed on the rotating shaft, and the torsion spring is used to drive the rotating shaft to rotate when the output shaft is at normal speed until the second bevel gear is away from the first bevel gear.

[0025] By adopting the above technical solution, when the abutting block abuts against the output shaft, causing the output shaft to stop rotating or return to normal speed, the torsion spring automatically drives the second bevel gear away from the first bevel gear. At this time, the abutting block no longer applies pressure to the output shaft, and the movable rod automatically resets, preparing for the next unexpected situation.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] By setting up transmission gears, spindles, pressure plates, and abutment plates, when the load on the output shaft exceeds the rated load, the transmission gears slip against the abutment plates, and the drive source cannot drive the spindle to rotate through the transmission gears, thus preventing the load from being lifted. This can prevent the electric hoist from lifting loads exceeding the rated load.

[0028] By setting a rotation limiter, if the operator violates regulations after the goods are lifted and increases the weight of the goods beyond the rated load, the transmission gear and the abutment plate may slip, the output shaft may lose its rotation limit, and the goods may suddenly fall, causing a serious accident. In this case, the rotation limiter can restrict the rotation of the output shaft after it loses control, thus limiting the fall of the goods and reducing the probability of an accident. Attached Figure Description

[0029] Figure 1 is a schematic diagram of the overall structure of the transmission mechanism in the embodiment of the application.

[0030] Figure 2 is a schematic diagram of the overall structure of the safety electric hoist according to an embodiment of this application.

[0031] Figure 3 is a structural schematic diagram of the rotation limiter in the safety electric hoist according to an embodiment of this application.

[0032] Figure 4 is a structural schematic diagram of the speed measuring drive component in the safety electric hoist according to an embodiment of this application.

[0033] Figure 5 is a cross-sectional view along line AA in Figure 2.

[0034] Figure 6 is a schematic diagram of the cooperation between the inner rotating block and the outer rotating block in the safety electric hoist of this application embodiment.

[0035] Explanation of reference numerals in the attached drawings: 1. Mandrel; 11. Transmission gear; 12. Abutment plate; 13. Pressure plate; 14. Abutment component; 141. Pressing block; 15. Friction plate; 16. Main gear; 2. Hoist body; 22. Output shaft; 221. Secondary gear; 23. Wire rope; 24. Hook; 25. Connecting frame; 3. Rotation limiter; 31. Drive component one; 311. First bevel gear; 312. Second bevel gear; 313. Second gear; 314. Movable rod; 315. Extension rod; 3151. Inclined surface; 32. Moving rod; 321. Abutment block; 322. Throttle; 33. First gear; 331. Rotating ring; 34. Speed ​​measuring drive component; 341. Push block; 3411. Arc block; 342. Rotating shaft; 3421. Torsion spring; 343. Rotating roller; 344. Outer rotating block; 3441. Receiving groove; 3442. Arc groove; 345. Inner rotating block; 3451. First groove; 346. Balance block; 347. Slider; 348. Spring; 35. Limiting rod. Detailed Implementation

[0036] The present application will be further described in detail below with reference to Figures 1-6.

[0037] This application discloses a transmission mechanism.

[0038] Referring to Figure 1, the transmission mechanism of this embodiment includes an abutment 14, a transmission gear 11, a splined spindle 1, two friction plates 15, two pressure plates 13, and two abutment plates 12. The spline on the spindle 1 passes through the inner ring of the transmission gear 11. The transmission gear 11 itself is not splined connected to the spindle 1. The abutment plates 12 and the pressure plates 13 are splined connected to the spindle 1. The two abutment plates 12 are located on both sides of the transmission gear 11, and the two pressure plates 13 are located on both sides of the two abutment plates 12. The two friction plates 15 are fixed on the two sides of the transmission gear 11 facing the two pressure plates 13. In other embodiments, the two friction plates 15 can also be fixed on the two sides of the two abutment plates 12 facing the transmission gear 11.

[0039] Referring to Figure 1, the clamping component includes two clamping blocks 141, which are threaded onto the spindle 1. The two clamping blocks 141 are located on both sides of the two pressure plates 13. The operator adjusts the clamping force of the clamping blocks 141 on the pressure plates 13 by rotating the clamping blocks 141. The transmission gear 11 is driven to rotate by the drive source of the electric hoist. The spindle 1 is used to drive the output shaft 22 of the electric hoist. When the load on the output shaft 22 is less than the rated load, the transmission gear 11 rotates synchronously with the abutment plate 12. When the load on the output shaft 22 exceeds the rated load, the transmission gear 11 slips against the abutment plate 12.

[0040] Referring to Figure 1, when the load on the output shaft 22 is less than the rated load, the transmission gear 11 and the abutment plate 12 can move synchronously under the friction force of the friction plate 15. When the drive source drives the transmission gear 11 to rotate, the transmission gear 11 drives the abutment plate 12 to rotate synchronously, and the synchronous belt drives the spline-connected spindle 1 to rotate. Finally, the spindle 1 drives the output shaft 22 to rotate, thus realizing the lifting of the load. When the load on the output shaft 22 exceeds the rated load, the transmission gear 11 and the abutment plate 12 slip, and the drive source cannot drive the spindle 1 to rotate through the transmission gear 11, thus failing to lift the load. This prevents the electric hoist from lifting loads exceeding the rated load.

[0041] This application also discloses a safety type electric hoist.

[0042] Referring to Figures 2 and 3, the safety electric hoist of this embodiment includes a hoist body 2, a rotation limiter 3, an output shaft 22, a hook 24, and a wire rope 23. The hoist body 2 is used to move on a beam. The output shaft 22 and the spindle 1 are both rotatably connected to the hoist body 2. The axes of the output shaft 22 and the spindle 1 are parallel to each other and horizontally arranged. A motor is fixed inside the hoist body 2, and the motor's rotating shaft 342 is coaxially fixedly connected to the spindle 1. A main gear 16 is coaxially fixed on the spindle 1, and a secondary gear 221 is coaxially fixed on the output shaft 22. The diameter of the main gear 16 is smaller than the diameter of the secondary gear 221, and the main gear 16 is meshed with the secondary gear 221. The wire rope 23 can be a wire chain rope or a braided wire rope. In this embodiment, a wire chain rope is used. A winding box is mounted on the hoist body 2, and a winding device is coaxially fixed on the output shaft 22. The winding device has multiple chain grooves that match the wire chain rope. One end of the wire rope 23 is fixed to the winding box, and the other end of the wire rope 23 passes around the winding device and is then fixed to the hook 24. In other embodiments, a braided wire rope can be used. One end of the braided wire rope is fixed to the output shaft 22 and wound around it, and the other end is fixed to the hook 24. When the output shaft 22 rotates, the wire rope 23 drives the hook 24 to rise and fall smoothly. When the rotation speed of the output shaft 22 exceeds the normal value, the rotation limiter 3 is used to limit the rotation of the output shaft 22.

[0043] Referring to Figures 2 and 3, if the operator violates regulations after the goods are lifted and adds other goods to the lifted goods without authorization, making the total weight of the goods exceed the rated load, this could seriously cause the transmission gear 11 to slip against the abutment plate 12, the output shaft 22 to lose its rotation restriction, and the goods to suddenly fall, resulting in a serious accident. At this time, the rotation limiter 3 can restrict the rotation of the output shaft 22 after it loses control, thus limiting the fall of the goods and reducing the probability of an accident.

[0044] Referring to Figures 2 and 3, the limiting component 3 includes a drive component 31, an abutment block 321, a moving rod 32, and a first gear 33. The axis of the first gear 33 is perpendicular to the axis of the output shaft 22. The first gear 33 is rotatably connected inside the hoist body 2. A rotating ring 331 is coaxially inserted and fixed on the first gear 33, and the rotating ring 331 is also rotatably connected inside the hoist body 2. The moving rod 32 is slidably connected to the hoist body 2 along an axis parallel to the first gear 33. The moving rod 32 is coaxially inserted and threadedly connected to the rotating ring 331. The drive component 31 drives the first gear 33 to rotate. The abutment block 321 is fixed to one end of the moving rod 32 facing the output shaft 22. The abutment block 321 is set directly opposite the output shaft 22. An arc groove matching the outer wall of the output shaft 22 is opened on the side of the abutment block 321 facing the output shaft 22. The abutment block 321 has a certain degree of deformability. When the output shaft 22 rotates too fast, the abutment block 321 is used to abut against the output shaft 22 to limit the rotation of the output shaft 22.

[0045] Referring to Figure 3, the moving rod 32 is located below the output shaft 22, and the moving rod 32 is located on one side of the output shaft 22 in the radial direction.

[0046] Referring to Figures 3 and 4, the drive component 31 includes a speed-measuring drive component 34, a first bevel gear 311, a second bevel gear 312, a second gear 313, and a movable rod 314. The second gear 313 is rotatably connected inside the hoist body 2 along an axis parallel to the first gear 33, and meshes with the first gear 33. The movable rod 314 is coaxially inserted and slidably connected to the second gear 313 along an axis parallel to the second gear 313. The movable rod 314 can slidably connect to the hoist body 2 and can also rotate with the second gear 313 while connected to the hoist body 2. When the second gear 313 rotates, it can drive the movable rod 314 to rotate synchronously inside the hoist body 2. The first bevel gear 311 is coaxially fixedly sleeved on the output shaft 22, and the second bevel gear 312 is coaxially fixedly sleeved on the top end of the movable rod 314. The second bevel gear 312 is used to mesh with the first bevel gear 311.

[0047] Referring to Figures 3 and 4, the speed measuring drive 34 is used to measure the rotational speed of the output shaft 22 and drive the movable rod 314 to slide on the second gear 313. When the rotational speed of the output shaft 22 exceeds the normal value, the speed measuring drive 34 drives the movable rod 314 to move until the first bevel gear 311 meshes with the second bevel gear 312. The output shaft 22 drives the movable rod 314 to rotate through the cooperation of the first bevel gear 311 and the second bevel gear 312. The movable rod 314 then drives the second gear 313 to rotate. The second gear 313 meshes with the first gear 33, driving the first gear 33 and the rotating ring 331 to rotate. The rotation of the rotating ring 331 drives the abutment block 321, which is threadedly connected to the rotating ring 331, to move toward the output shaft 22, thus slowing down the output shaft 22. Throughout the process, the force of the output shaft 22's own rotation is used to control the abutment force of the abutment block 321 on the output shaft 22. By using the force of the abutment block to stop the force, the rotation of the output shaft 22 is cleverly restricted.

[0048] Referring to Figures 4 and 5, the speed measuring drive component 34 includes a push block 341, a rotating shaft 342, a rotating roller 343, an outer rotating block 344, and an inner rotating block 345. The rotational speed of the output shaft 22 is indirectly measured by measuring the winding and unwinding speed of the wire rope 23. The wire rope 23 extends from the bottom end of the hoist body 2. Two connecting frames 25 are fixed on the bottom surface of the hoist body 2, and the two connecting frames 25 are respectively located on both sides of the wire rope 23. The rotating roller 343 is rotatably connected to the connecting frames 25. The axis of the rotating roller 343 is horizontally arranged and perpendicular to the axis of the output shaft 22. The rotating roller 343 abuts against the wire rope 23 and can rotate with the winding and unwinding of the wire rope 23. In this embodiment, the surface of the wire chain is covered with a rubber sleeve with high friction, so it can drive the rotating roller 343 to rotate. The inner rotating block 345 is coaxially fixed to one end of the rotating roller 343, and the other end of the rotating ring 331 is coaxially fixed to the balance block 346 of the balance rotating roller 343.

[0049] Referring to Figures 4 and 5, the rotating shaft 342 is rotatably connected to the hoist body 2. The rotating shaft 342 is located on one side of the rotating roller 343 and is coaxially arranged with the rotating roller 343. The push block 341 is always slidably connected to the hoist body 2 along the axis parallel to the rotating shaft 342. The end of the rotating shaft 342 away from the rotating roller 343 is threaded through and connected to the push block 341. An extension rod 315 is coaxially rotatably connected to the bottom end of the movable rod 314. The extension rod 315 is slidably connected to the hoist body 2 along a direction parallel to the axis of the movable rod 314. An inclined surface 3151 is provided on the bottom surface of the extension rod 315 facing the push block 341. An arc-shaped block 3411 protruding towards the inclined surface 3151 is fixed at the top end of the push block 341 away from the rotating shaft 342. Under the action of gravity, the movable rod 314 and the extension rod 315 always have a downward tendency. The arc-shaped block 3411 can always abut against the inclined surface 3151. The push block 341 is used to push the extension rod 315 and the movable rod 314 to move.

[0050] Referring to Figures 5 and 6, the outer rotating block 344 is coaxially fixed to one end of the rotating shaft 342 near the rotating roller 343. A receiving groove 3441 is formed on the side of the outer rotating block 344 near the inner rotating block 345, and the inner rotating block 345 is located in the receiving groove 3441. A plurality of first grooves 3451 are evenly formed on the circumferential outer wall of the inner rotating block 345. The depth direction of the first grooves 3451 is perpendicular to the axial direction of the inner rotating block 345. A slider 347 is slidably connected in the first groove 3451 along the depth direction of the first groove 3451. A spring 348 is fixed on the slider 347. The two ends of the spring 348 are respectively fixed on the bottom wall of the first groove 3451 and on the side of the slider 347 facing the bottom wall of the first groove 3451. The end of the slider 347 away from the bottom wall of the first groove 3451 is arc-shaped and protrudes in the direction away from the first groove 3451. Multiple arc-shaped grooves 3442 matching the end of the slider 347 are sequentially opened on the circumferential inner wall of the receiving groove 3441.

[0051] Referring to Figures 5 and 6, when the output shaft 22 stops rotating or is at its normal speed, the slider 347 is positioned within the first groove 3451 under the action of the spring 348. When the speed of the output shaft 22 exceeds the normal value, the slider 347 moves out of the first groove 3451 under the action of centrifugal force, and the end of the slider 347 is embedded in the corresponding arc-shaped groove 3442. The inner rotating block 345 and the outer rotating block 344 rotate synchronously.

[0052] Referring to Figures 4 and 6, the rotating roller 343 abuts against the wire rope 23, and the rotating roller 343 can be driven to rotate by the wire rope 23, thereby indirectly and accurately reflecting the rotation speed of the output shaft 22 at this time. When the cargo is overloaded and falls freely, the rotation speed of the rotating roller 343 exceeds the normal value. The rotating roller 343 drives the inner rotating block 345 to rotate rapidly. The slider 347 moves out of the first groove 3451 under the action of centrifugal force and drives the outer rotating block 344 to rotate. The rotation of the outer rotating block 344 then drives the rotating shaft 342 to rotate. The rotation of the rotating shaft 342 drives the push block 341 threadedly connected to the rotating shaft 342 to slide on the hoist body 2, so that the push block 341 acts on the extension rod 315 and drives the movable rod 314 to move towards the output shaft 22. Finally, the first bevel gear 311 and the second bevel gear 312 on the movable rod 314 are meshed. Then, through a series of linkages, the abutment block 321 can restrict the rotation of the output shaft 22 in time.

[0053] Referring to Figures 5 and 6, a torsion spring 3421 is installed on the rotating shaft 342. The torsion spring 3421 is used to drive the rotating shaft 342 to rotate when the output shaft 22 is in a stopped state or at normal speed, until the second bevel gear 312 moves away from the first bevel gear 311. When the abutment block 321 abuts against the output shaft 22, causing the output shaft 22 to stop rotating or return to normal speed, the torsion spring 3421 automatically drives the second bevel gear 312 away from the first bevel gear 311. At this time, the abutment block 321 no longer applies pressure to the output shaft 22, and the movable rod 314 automatically resets, preparing for the next unexpected situation.

[0054] Referring to Figures 3 and 5, the end of the moving rod 32 furthest from the abutment block 321 always extends out of the hoist body 2 and is fixed with a handle 322 for manual force application. A limiting rod 35 is also slidably connected to the hoist body 2 along a sliding direction parallel to the moving rod 32. The limiting rod 35 is used to engage with the tooth groove of the first gear 33 to limit its rotation. After the abutment block 321 restricts the rotation of the output shaft 22, the operator needs to handle any unexpected situations. The operator first drives the motor to stop, then pushes the limiting rod 35 to restrict the rotation of the first gear 33, and then adjusts the contact force between the abutment block 321 and the output shaft 22 by rotating the handle 322 until the goods are smoothly transported to the ground. Then, rotating the handle 322 again moves the abutment block 321 away from the output shaft 22, no longer applying pressure to the output shaft 22, in preparation for the next unexpected situation.

[0055] The implementation principle of a safety-type electric hoist and its transmission mechanism in this application embodiment is as follows: When the load on the output shaft 22 exceeds the rated load, the transmission gear 11 slips against the abutment plate 12, preventing the motor from driving the spindle 1 to rotate through the transmission gear 11, thus preventing the hoist from lifting goods exceeding the rated load. If the operator violates regulations and increases the weight of the goods after lifting, making the weight of the goods exceed the rated load, it will seriously cause the transmission gear 11 to slip against the abutment plate 12, and the output shaft 22 to lose its rotation restriction. The goods will suddenly fall, causing a serious accident. At this time, the rotation limiter 3 can restrict the rotation of the output shaft 22 after it loses control, which can promptly limit the fall of the goods and reduce the probability of an accident.

[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A safety-type electric hoist, characterized in that: The system includes a transmission mechanism comprising an abutment (14), a transmission gear (11), a splined spindle (1), a pressure plate (13), and an abutment plate (12). The spline on the spindle (1) passes through the inner ring of the transmission gear (11). The spindle (1) is splinedly connected to the abutment plate (12). The pressure plate (13) is sleeved on the spindle (1). The abutment plate (12) is located on one side of the transmission gear (11), and the pressure plate (13) is located on the abutment plate (12). On the side away from the transmission gear (11), a friction plate (15) is fixed on the side of the transmission gear (11) facing the pressure plate (13) or the side of the abutment plate (12) facing the transmission gear (11). The abutment member (14) is used to adjust the position of the pressure plate (13) on the spindle (1) and to press the pressure plate (13) against the abutment plate (12). The abutment plate (12) presses against the friction plate (15). The spindle (1) is used to drive the output shaft of the lifting equipment. 22), the transmission gear (11) is rotatably connected to the lifting equipment and driven to rotate by the driving source of the lifting equipment. When the load on the output shaft (22) exceeds the rated load, the transmission gear (11) slips against the abutment plate (12). The safety electric hoist also includes a rotation limiter (3), a hoist body (2), an output shaft (22), a hook (24), and a wire rope (23). The output shaft (22) and the spindle (1) are rotatably connected to the hoist body (2). A main gear (16) is coaxially fixed on the spindle (1), and a secondary gear (221) is coaxially fixed on the output shaft (22). The main gear (16) is meshed with the secondary gear (221). One end of the wire rope (23) is wound around the output shaft (22), and the other end of the wire rope (23) is fixed to the hook (24). When the load on the output shaft (11) exceeds the rated load, the transmission gear (11) slips against the abutment plate (12). When the rotational speed of the output shaft (22) exceeds the normal value, the rotation limiting component (3) is used to limit the rotation of the output shaft (22); the rotation limiting component (3) includes a drive component (31), a stop block (321), a moving rod (32) and a first gear (33). The axis of the first gear (33) is perpendicular to the axis of the output shaft (22). The first gear (33) is rotatably connected to the hoist body (2) along the axis of the first gear (33). A rotating ring (331) is coaxially inserted and fixed on the first gear (33). The moving rod (32) is slidably connected to the hoist body (2) along the axis parallel to the first gear (33). The moving rod (32) is coaxially inserted and threadedly connected to the rotating ring (331). The stop block (321) is fixed on the moving rod (32) facing the output shaft (22). At one end of the output shaft (22), the drive member (31) drives the first gear (33) to rotate, and the abutment block (321) is used to abut against the output shaft (22) to restrict the rotation of the output shaft (22);The drive component (31) includes a speed measuring drive component (34), a first bevel gear (311), a second bevel gear (312), a second gear (313), and a movable rod (314). The second gear (313) is rotatably connected to the hoist body (2) along an axis parallel to the first gear (33), and the second gear (313) meshes with the first gear (33). The movable rod (314) is coaxially inserted and slidably connected to the second gear (313) along an axis parallel to the second gear (313), and the movable rod (314) rotatably connects to the hoist body (2) following the second gear (313). The first bevel gear (311) is coaxially fixedly sleeved on the output shaft (22), and the second bevel gear (312) is coaxially fixedly sleeved on the movable rod (314). The speed measuring drive component (34) is used to measure the output shaft (22). The rotational speed of the output shaft (22) drives the movable rod (314) to slide on the second gear (313). When the rotational speed of the output shaft (22) exceeds the normal value, the speed measuring drive (34) drives the movable rod (314) to move to the point where the first bevel gear (311) meshes with the second bevel gear (312), and the abutment block (321) moves toward the output shaft (22).

2. The safety-type electric hoist according to claim 1, characterized in that: The speed measuring drive component (34) includes a push block (341), a rotating shaft (342), a rotating roller (343), an outer rotating block (344), and an inner rotating block (345). The rotating roller (343) is rotatably connected to the hoist body (2). The axis of the rotating roller (343) is perpendicular to the axis of the output shaft (22). The rotating roller (343) abuts against one of the wire ropes (23) and rotates with the winding and unwinding of the wire rope (23). The inner rotating block (345) is coaxially fixed on the rotating roller (343). The rotating shaft (342) is rotatably connected to the hoist body (2). The rotating shaft (342) and the rotating roller (343) are coaxially arranged. The pushing block (341) is slidably connected to the hoist body (2) along the axis parallel to the rotating shaft (342). One end of the rotating shaft (342) is threaded through and connected to the pushing block (341). The movable rod (314) is located below the output shaft (22). The pushing block (341) abuts against the movable rod (314) and is used to push the movable rod (314) to move toward the output shaft (22). The outer rotating block (344) is coaxially fixed on the rotating shaft (342). A receiving groove (3441) is provided on one side of the outer rotating block (344). The inner rotating block (345) is located in the receiving groove (3441). A first groove (3451) is provided on the circumferential outer wall of the inner rotating block (345). A slider (347) is slidably connected to the first groove (3451) along the depth direction of the first groove (3451). A spring (348) is provided on the slider (347). The two ends of the spring (348) are respectively fixed on the bottom wall of the first groove (3451) and the slider (347). When the output shaft (22) is working normally, the slider (347) is located in the first groove (3451). When the output shaft (22) is working normally, the slider (347) is located in the first groove (3451). When the rotational speed of 22) exceeds the normal value, the slider (347) moves out of the first groove (3451) under the action of centrifugal force and abuts against the circumferential inner wall of the receiving groove (3441), and the slider (347) drives the outer rotating block (344) to rotate.

3. The safety-type electric hoist according to claim 2, characterized in that: The end of the slider (347) away from the bottom wall of the first groove (3451) is arc-shaped and protrudes towards the side away from the first groove (3451). Multiple arc-shaped grooves (3442) matching the end of the slider (347) are sequentially opened on the circumferential inner wall of the receiving groove (3441). When the rotational speed of the output shaft (22) exceeds the normal value, the end of the slider (347) is embedded in one of the arc-shaped grooves (3442).

4. The safety-type electric hoist according to claim 3, characterized in that: The movable rod (314) is rotatably connected to an extension rod (315) at one end near the push block (341). The extension rod (315) is slidably connected to the hoist body (2) along the axis parallel to the movable rod (314). An inclined surface (3151) is provided on the bottom surface of the extension rod (315) facing the push block (341). An arc-shaped block (3411) protruding towards the inclined surface (3151) is fixed on the push block (341). The arc-shaped block (3411) always abuts against the inclined surface (3151).

5. The safety-type electric hoist according to claim 3, characterized in that: A torsion spring (3421) is installed on the shaft (342), and the torsion spring (3421) is used to drive the shaft (342) to rotate when the output shaft (22) is at normal speed until the second bevel gear (312) moves away from the first bevel gear (311).

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