Trolley capable of converting gravitational potential energy into kinetic energy
By designing a small cart that converts gravity potential energy into kinetic energy, the problem of insufficient force in traditional human trolleys is solved and more efficient heavy cargo transportation is achieved.
Patent Information
- Application Number
- CN202411565287.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-02-11
AI Technical Summary
When transporting heavy carts, especially when climbing hills, traditional human trolleys require a lot of manpower and time, and it is difficult to climb the hill smoothly.
A small cart was designed that solves the problem of insufficient force when transporting heavy cargo by converting gravity potential energy into kinetic energy. The small cart includes a chassis, a hopper, a drive shaft, an active wheel and a driven wheel. Through gears and transmission devices, the gravitational potential energy of the material on the hopper is converted into kinetic energy, and the wheels are pushed forward.
It enables more ease in driving heavy goods during hill climbing or long-distance transportation, reducing manpower consumption and time, and improving transportation efficiency.
Smart Images
Figure CN119408593A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of wheelbarrows, and in particular relates to a wheelbarrow which converts gravitational potential energy into kinetic energy. Background Art
[0002] Various places have successively introduced policies that electric carts are not allowed to go up elevators. From picking up goods to the designated unloading location on the floor, they can only be transported by stairs or by rickshaws throughout the whole process. However, traditional rickshaws can only use human-powered carts to transport goods that are difficult to transport, such as concrete. Due to the heavy weight of goods such as concrete, it will be very laborious or impossible to climb the slope smoothly when using human-powered carts during transportation. If a small amount of multiple transportation is adopted, although the normal transportation of goods can be guaranteed, it will consume a lot of manpower and time. Summary of the invention
[0003] The object of the present invention is to provide a small cart which can convert gravitational potential energy into kinetic energy.
[0004] The present invention is achieved by the following measures: a small cart for converting gravitational potential energy into kinetic energy, characterized by comprising a chassis, a hopper arranged on the chassis, and a handrail arranged above one end of the chassis; A driving shaft is disposed at one end of the chassis, driving wheels are disposed at both ends of the driving shaft, and driven wheels are symmetrically disposed at the other end of the chassis; Guide rods are arranged at the four corners of the chassis, the hopper is sleeved on the guide rods, and a guide ring cooperating with the guide rods is arranged on the side wall of the hopper; A rack is fixedly provided on the outer wall of the hopper, a small gear meshing with the rack is rotatably provided on the chassis through a mounting frame, and a large gear is coaxially fixedly provided on the shaft of the small gear; A transmission shaft and a brake shaft are arranged in the middle of the chassis, the axes of which are perpendicular to the axis of the drive shaft. The transmission shaft includes a first shaft and a second shaft. Crown gears are arranged at the connecting ends of the first shaft and the second shaft, and at the connecting ends of the second shaft and the brake shaft. The transmission shaft is rotatably connected, and the brake shaft is fixedly connected. The second shaft is provided with a tooth column meshing with the large gear, and the first shaft and the driving shaft are driven by a bevel gear; It also includes a locking structure for the hopper and a control structure for controlling the separation and engagement of the crown gear.
[0005] The number of teeth of the large gear is generally 2-5 times that of the small gear and the gear column.
[0006] The driven wheel can be a universal wheel, which mainly controls the direction. When changing the direction, the torque required is small. Therefore, it is more labor-saving when turning. The driving wheel is a directional wheel. When walking in a straight line, the force required for the arm to control the direction is small, and it is more flexible when turning.
[0007] The locking structure is a brake structure for locking the large gear. The brake structure adopts a disc brake in the prior art, and the controller of the disc brake is arranged on the armrest. The disc brake housing is fixed on the chassis or the lower part of the armrest. The two brake pads of the disc brake are located on both sides of the large gear.
[0008] The guide rod is a lead screw, the guide ring is a lead screw nut, the lead screw nut and the hopper are connected via a bearing, the outer ring of the bearing is fixedly connected to the hopper, and the inner ring of the bearing is fixedly connected to the lead screw nut. The upper end of the lead screw extends into the guide ring.
[0009] The chassis includes a rectangular steel frame, which includes two side plates and two end plates, a first mounting plate and a second mounting plate are arranged between the two side plates, the first shaft is rotatably arranged on the first mounting plate, the second shaft is rotatably arranged on the second mounting plate, and the brake shaft is fixedly arranged on the end plate close to the armrest; the rotation connection between the first shaft and the second shaft is generally realized by bearings.
[0010] The control structure comprises guide rods symmetrically arranged on both sides of the second shaft, the guide rods are slidably arranged on the second mounting plate and the rectangular steel frame, the two guide rods are fixedly connected to the second shaft through a connecting rod, and one end of the guide rod facing the first mounting plate is connected to the first mounting plate through a spring 1; A first pedal and a second pedal are rotatably arranged on the mounting frame, the inner end of the first pedal is connected to one of the connecting rods via a steel wire rope, a buckle is arranged at the inner end of the second pedal, and a first slot and a second slot cooperating with the buckle are arranged on the guide rod corresponding to the second pedal; a guide wheel for the steel wire rope is arranged on the chassis, and the steel wire rope passes under the guide wheel.
[0011] The second slot is close to the handrail, the buckle is in the first slot, and the second shaft is not connected to the first shaft and the brake shaft; the buckle is in the second slot, the second shaft is connected to the brake shaft, the buckle is not in the first slot and the second slot, and the first shaft and the second shaft are connected. The second shaft is connected to the brake shaft to brake the second shaft, thereby preventing the hopper from rising or falling.
[0012] A second spring is sleeved on the lead screw, and the automatic resetting of the hopper can be assisted by the action of the second spring.
[0013] The driving shaft is rotatably arranged on the two side plates and a first bevel gear is arranged on the driving shaft, and a second bevel gear meshing with the first bevel gear is arranged at one end of the first shaft close to the driving shaft; The hopper includes a rectangular frame, a bottom plate arranged on the rectangular frame, and side plates are arranged around the bottom plate. The inner ring of the bearing is fixed on the rectangular frame, and the rack is also fixed on the rectangular frame. The front side plate and the left and right side plates are preferably connected to the bottom plate by hinges, which can facilitate the subsequent unloading. The connecting ends of the left and right side plates and the front side plate can be connected by a limiter, and the existing latch can be used.
[0014] The lower end of the lead screw is fixed on the chassis, generally by welding. The lead screw uses a ball screw to ensure the synchronous lifting of the hopper; the bearing uses an angular contact ball bearing, so that a stable and reliable platform can be formed through four guide rods, which can ensure that the four corners will not be out of sync during the lifting process. Since this system shaft is subject to axial force, an angular contact ball bearing is selected.
[0015] The chassis, rectangular steel frame and mounting frame are all made of light steel.
[0016] Working principle: The hopper is at a high position and loaded with materials, the buckle is in the second slot, the first shaft and the second shaft do not transmit, the second shaft is connected to the brake shaft to brake the second shaft, at this time the large gear meshing with the second shaft cannot rotate, and the small gear coaxial with the large gear cannot rotate, the rack and the hopper fixedly connected to the rack cannot move up and down, and the hopper cannot drop even if there is material on it; When the hopper needs to be lowered, the second pedal is stepped on, the buckle is lifted and disengaged from the second slot, and the second shaft moves toward the first shaft under the action of spring 1 to connect the first shaft and the second shaft, and the hopper is lowered under the action of the gravity of the material, and the rack drives the pinion to rotate, and the large gear coaxial with the pinion rotates accordingly, and the large gear drives the gear column on the second shaft to rotate. Since the second shaft and the first shaft are in a transmission state, the first shaft rotates with the gear column on the second shaft, and the second bevel gear on the first shaft drives the first bevel gear meshing therewith to rotate, and the first bevel gear drives the drive shaft and the active wheel on the drive shaft to rotate, thereby converting the gravitational potential energy of the material into kinetic energy; When the hopper stops descending, the butterfly brake is activated to brake the large gear briefly. At this time, the hopper cannot descend and both the active wheel and the driven wheel cannot move normally. The first pedal is slightly stepped on, and the wire rope pulls the connecting rod connected to the second shaft to move away from the first shaft. The buckle first enters the first slot, and the second shaft is separated from the first shaft. At this time, the wheel resumes normal movement. Continue to step on the first pedal, and the second shaft continues to move until the crown teeth on the second shaft and the brake shaft are engaged and the buckle is stuck in the second slot. The second shaft cannot rotate, and the disc brake is released. At this time, the hopper cannot descend. Through the cooperation of the disc brake and the first pedal, the hopper with materials can be lowered at any time, so that the gravitational potential energy can be released in multiple times instead of all at once, so as to be suitable for multiple small slope roads.
[0017] In addition, after the materials are transported to the designated location, in order to facilitate unloading of the materials, the side panels connected by hinges can be rotated to achieve rapid unloading of the materials.
[0018] When the hopper drops to the lowest point, it can be lifted in the following two ways: 1. Connect the first shaft and the second shaft, and change the forward push to the backward pull, that is, make the wheels move in the opposite direction, and realize the lifting of the hopper through directional transmission.
[0019] 2. Separate the second axis from the first axis, and the second axis from the third axis, and use the spring 2 on the screw to realize the lifting of the hopper. At this time, the staff can apply force to cooperate with the spring 2 to lift the hopper (that is, the hopper is in an unloaded state, and under the action of the spring 2, the hopper is at the highest point).
[0020] The beneficial effect of the technical solution provided by the embodiment of the present invention is: by separating and combining the second shaft with the first shaft and the brake shaft, it is ensured that the heavy object is braked without completing the work, and the device can still move forward, which makes it more convenient to continuously climb slopes in different positions.
[0021] The reason why traditional carts have small capacity is that the larger the capacity, the more cargo it can carry and the more difficult it is to climb a slope. The greater the load capacity of this device, the greater the power it provides, so it can provide more capacity than other carts.
[0022] The hopper can be reset directly by spring 2 or by reversing the wheel.
[0023] The synchronous lifting structure composed of lead screws can ensure that the hopper can be lifted synchronously and smoothly, avoiding device failure and damage caused by asynchronous lifting.
[0024] The rack contacts the pinion, the pinion is connected to the large gear, and the large gear meshes with the gear column. After transmission, the speed of the second shaft transmitted to the driving wheel becomes larger. Through this size relationship, the entire device can move forward farther. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings used in the embodiments. Obviously, the drawings listed below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0026] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 yes Figure 1 A partial enlarged view of the middle A; Figure 3 yes Figure 1 A partial enlarged view of point B in the middle; Figure 4 is a schematic structural diagram of the bottom of an embodiment of the present invention; Figure 5 yes Figure 4 A partial enlarged view of point C in the middle; Figure 6 is with Figure 1 Schematic diagram of the structure at different angles; Figure 7 It is a schematic diagram of the structure of the embodiment of the present invention after removing the hopper, the large gear and the disc brake; Figure 8 yes Figure 7 A partial enlarged view of point D in the middle.
[0027] In the accompanying drawings, the list of components represented by each reference numeral is as follows: 1. chassis; 2. hopper; 3. drive shaft; 4. driven wheel; 5. screw; 6. bearing; 7. first shaft; 8. second shaft; 9. disc brake; 10. crown gear; 11. first bevel gear; 12. second bevel gear; 13. guide rod; 14. connecting rod; 15. spring 1; 16. rack; 17. small gear; 18. large gear; 20. handrail; 21. brake shaft; 22. second pedal; 23. buckle; 24. guide wheel; 25. wire rope; 26. first pedal; 27. mounting frame; 101. first mounting plate; 102. second mounting plate; 201. guide ring; 202. rectangular frame; 301. driving wheel; 501. screw nut; 801. gear column; 901. controller; 1301. first slot. DETAILED DESCRIPTION
[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Of course, the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.
[0029] See also Figure 1-Figure 8 , a small cart that converts gravitational potential energy into kinetic energy, characterized in that it includes a chassis 1, a hopper 2 arranged on the chassis 1, and a handrail 20 arranged above one end of the chassis 1; A driving shaft 3 is disposed at one end of the chassis 1, and driving wheels 301 are disposed at both ends of the driving shaft 3, and driven wheels are symmetrically disposed at the other end of the chassis 1; Guide rods are provided at the four corners of the chassis 1, the hopper 2 is sleeved on the guide rods, and a guide ring 201 cooperating with the guide rods is provided on the side wall of the hopper 2; A rack 16 is fixedly provided on the outer wall of the hopper 2, a pinion 17 meshing with the rack 16 is rotatably provided on the chassis 1 through a mounting frame 27, and a large gear 18 is coaxially fixedly provided on the shaft of the pinion 17; A transmission shaft and a brake shaft 21 are arranged in the middle of the chassis 1, and the axes thereof are perpendicular to the axis of the drive shaft 3. The transmission shaft comprises a first shaft 7 and a second shaft 8. Crown gears 10 are arranged at the connecting ends of the first shaft 7 and the second shaft 8, and at the connecting ends of the second shaft 8 and the brake shaft 21. The transmission shaft is rotatably connected, and the brake shaft 21 is fixedly connected. The second shaft 8 is provided with a tooth column 801 meshing with the large gear 18, and the first shaft 7 and the driving shaft 3 are driven by a bevel gear; It also includes a locking structure for the hopper 2 and a control structure for controlling the separation and engagement of the crown gear 10 .
[0030] The number of teeth of the large gear 18 is generally 2-5 times that of the small gear 17 and the gear column 801.
[0031] The driven wheel can be a universal wheel, which mainly controls the direction. When changing the direction, the torque required is small. Therefore, it is more labor-saving when turning. The driving wheel is a directional wheel. When walking in a straight line, the force required by the arm to control the direction is small, and it is more flexible when turning.
[0032] The locking structure is a brake structure for locking the large gear 18. The brake structure adopts the disc brake 9 in the prior art, and the controller 901 of the disc brake 9 is arranged on the handrail 20. The housing of the disc brake 9 is fixed to the chassis 1 or the lower part of the handrail 20. The two brake pads of the disc brake 9 are located on both sides of the large gear 18, and the disc brake 9 and the controller 901 of the disc brake both adopt the prior art.
[0033] The guide rod is a lead screw 5, the guide ring 201 is a lead screw nut 501, the lead screw nut 501 and the hopper 2 are connected via a bearing 6, the outer ring of the bearing 6 is fixedly connected to the hopper 2, and the inner ring of the bearing 6 is fixedly connected to the lead screw nut 501. The upper end of the lead screw 5 extends into the guide ring 201.
[0034] The chassis 1 includes a rectangular steel frame, which includes two side plates and two end plates. A first mounting plate 101 and a second mounting plate 102 are spaced apart between the two side plates. The first shaft 7 is rotatably set on the first mounting plate 101, and the second shaft 8 is rotatably set on the second mounting plate 102. The brake shaft 21 is fixedly set on the end plate near the armrest 20; the rotation connection between the first shaft 7 and the second shaft 8 is generally achieved by bearings.
[0035] The control structure includes guide rods 13 symmetrically arranged on both sides of the second shaft 8, the guide rods 13 are slidably arranged on the second mounting plate 102 and the rectangular steel frame, the two guide rods 13 are fixedly connected to the second shaft 8 through a connecting rod 14, and one end of the guide rod 13 facing the first mounting plate 101 is connected to the first mounting plate 101 through a spring 15; A first pedal 26 and a second pedal 22 are rotatably arranged on the mounting frame 27, the inner end of the first pedal 26 is connected to one of the connecting rods 14 via a steel wire rope 25, a buckle 23 is arranged at the inner end of the second pedal 22, and a first slot 1301 and a second slot cooperating with the buckle 23 are arranged on the guide rod 13 corresponding to the second pedal 22; a guide wheel 24 for the steel wire rope 25 is arranged on the chassis 1, and the steel wire rope 25 passes through the bottom of the guide wheel 24.
[0036] The second slot is close to the handrail 20, the buckle 23 is in the first slot 1301, and the second shaft 8 is not connected to the first shaft 7 and the brake shaft 21; the buckle 23 is in the second slot, the second shaft 8 is connected to the brake shaft 21, the buckle 23 is not in the first slot 1301 and the second slot, and the first shaft 7 is connected to the second shaft 8. The connection between the second shaft 8 and the brake shaft 21 can brake the second shaft 8, thereby preventing the hopper 2 from rising or falling.
[0037] A spring 2 is sleeved on the lead screw 5. Through the effect of the spring 2, the automatic resetting of the hopper 2 can be assisted.
[0038] The driving shaft 3 is rotatably arranged on the two side plates and a first bevel gear 11 is arranged on the driving shaft 3. A second bevel gear 12 meshing with the first bevel gear 11 is arranged at one end of the first shaft 7 close to the driving shaft 3. The hopper 2 includes a rectangular frame 202, a bottom plate arranged on the rectangular frame 202, and side plates arranged around the bottom plate. The inner ring of the bearing 6 is fixed on the rectangular frame 202, and the rack 16 is also fixed on the rectangular frame 202. The front side plate and the left and right side plates are preferably connected to the bottom plate by hinges, which can facilitate the subsequent unloading. The connecting ends of the left and right side plates and the front side plate can be connected by a limiter, and the existing latch can be used.
[0039] The lower end of the lead screw 5 is fixed on the chassis 1, generally by welding. The lead screw 5 uses a ball screw 5 to ensure the synchronous lifting of the hopper 2. The bearing 6 uses an angular contact ball bearing 6, so that a stable and reliable platform can be formed through four guide rods, which can ensure that the four corners will not be out of sync during the lifting process. Since the bearing 6 of this system is subjected to axial force, an angular contact ball bearing 6 is selected.
[0040] The chassis 1, the rectangular steel frame and the mounting frame 27 are all made of light steel.
[0041] Working principle: The hopper 2 is at a high position and loaded with materials, the buckle 23 is in the second slot, the first shaft 7 and the second shaft 8 are not transmitting, the second shaft 8 is connected to the brake shaft 21 to brake the second shaft 8, and the large gear 18 meshing with the second shaft 8 cannot rotate, and the small gear 17 coaxial with the large gear 18 cannot rotate, and the rack 16 and the hopper 2 fixedly connected to the rack 16 cannot move up and down. At this time, the hopper 2 cannot drop even if there is material on it; When the hopper 2 needs to be lowered, the second pedal 22 is stepped on, the buckle 23 is lifted and disengaged from the second slot, and the second shaft 8 moves toward the first shaft 7 under the action of the spring 15, so as to realize the connection between the first shaft 7 and the second shaft 8. The hopper 2 is lowered under the action of the gravity of the material, and the rack 16 drives the pinion 17 to rotate, and the large gear 18 coaxial with the pinion 17 rotates accordingly, and the large gear 18 drives the tooth column 801 on the second shaft 8 to rotate. Since the second shaft 8 and the first shaft 7 are in a transmission state, the first shaft 7 rotates with the tooth column 801 on the second shaft 8, and the second bevel gear 12 on the first shaft 7 drives the first bevel gear 11 meshing therewith to rotate, and the first bevel gear 11 drives the drive shaft 3 and the active wheel 301 on the drive shaft 3 to rotate, thereby converting the gravitational potential energy of the material into kinetic energy; When the hopper 2 stops descending, the disc brake is activated to brake the large gear 18 briefly. At this time, the hopper 2 cannot descend and the driving wheel 301 and the driven wheel 4 cannot move normally. The first pedal 26 is slightly stepped on, and the wire rope 25 pulls the connecting rod 14 connected to the second shaft 8 to move away from the first shaft 7. The buckle 23 first enters the first slot 1301, and the second shaft 8 is separated from the first shaft 7. At this time, the wheel resumes normal movement, and the first pedal 26 is continued to be stepped on again, and the second shaft 8 continues to move until the crown teeth on the second shaft 8 and the brake shaft 21 are engaged and the buckle 23 is stuck in the second slot. The second shaft 8 cannot rotate, and the disc brake 9 is released. At this time, the hopper 2 cannot descend. Through the cooperation of the disc brake 9 and the first pedal 26, the hopper 2 with materials can be lowered at any time, so that the gravitational potential energy can be released in multiple times, instead of being released at once, so as to be suitable for multiple small slope roads.
[0042] In addition, after the materials are transported to the designated location, in order to facilitate unloading of the materials, the side panels connected by hinges can be rotated to achieve rapid unloading of the materials.
[0043] When hopper 2 drops to the lowest point, the hopper 2 can be lifted in the following two ways: 3. Connect the first shaft 7 and the second shaft 8, and change the forward push to the backward pull, that is, make the wheels move in the opposite direction, and realize the lifting of the hopper 2 through directional transmission.
[0044] The second shaft 8 is separated from the first shaft 7 and the third shaft, and the hopper 2 is lifted up by the spring 2 on the screw 5. At this time, the staff can apply force to cooperate with the spring 2 to lift the hopper 2 (that is, the hopper 2 is in an unloaded state, and under the action of the spring 2, the hopper 2 is at the highest point).
[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A cart that converts gravitational potential energy into kinetic energy, characterized in that: It includes a chassis, a hopper arranged on the chassis, and a handrail arranged above one end of the chassis; A driving shaft is disposed at one end of the chassis, driving wheels are disposed at both ends of the driving shaft, and driven wheels are symmetrically disposed at the other end of the chassis; Guide rods are arranged at the four corners of the chassis, and the hopper is sleeved on the guide rods; A rack is fixedly provided on the outer wall of the hopper, a small gear meshing with the rack is rotatably provided on the chassis through a mounting frame, and a large gear is coaxially fixedly provided on the shaft of the small gear; A transmission shaft and a brake shaft are arranged in the middle of the chassis, the axes of which are perpendicular to the axis of the drive shaft. The transmission shaft includes a first shaft and a second shaft. Crown gears are arranged at the connecting ends of the first shaft and the second shaft, and at the connecting ends of the second shaft and the brake shaft. The transmission shaft is rotatably connected, and the brake shaft is fixedly connected. The second shaft is provided with a tooth column meshing with the large gear, and the first shaft and the driving shaft are driven by a bevel gear; It also includes a locking structure for the hopper and a control structure for controlling the separation and engagement of the crown gear.
2. The cart for converting gravitational potential energy into kinetic energy according to claim 1, characterized in that: The locking structure is a brake structure for locking the large gear.
3. The cart for converting gravitational potential energy into kinetic energy according to claim 1, characterized in that: The guide rod adopts a lead screw, the guide ring is a lead screw nut, the lead screw nut and the hopper are connected through a bearing, the outer ring of the bearing is fixedly connected to the hopper, and the inner ring of the bearing is fixedly connected to the lead screw nut.
4. The cart for converting gravitational potential energy into kinetic energy according to claim 1, characterized in that: The chassis comprises a rectangular steel frame, the rectangular steel frame comprises two side plates and two end plates, a first mounting plate and a second mounting plate are arranged between the two side plates, the first shaft is rotatably arranged on the first mounting plate, the second shaft is rotatably arranged on the second mounting plate, and the brake shaft is fixedly arranged on the end plate close to the handrail; The control structure comprises guide rods symmetrically arranged on both sides of the second shaft, the guide rods are slidably arranged on the second mounting plate and the rectangular steel frame, the two guide rods are fixedly connected to the second shaft through a connecting rod, and one end of the guide rod facing the first mounting plate is connected to the first mounting plate through a spring 1; The mounting frame is rotatably provided with a first pedal and a second pedal, the inner end of the first pedal is connected to one of the connecting rods through a steel wire rope, the inner end of the second pedal is provided with a buckle, and the guide rod corresponding to the second pedal is provided with a first slot and a second slot matched with the buckle; The second slot is close to the armrest, the buckle is in the first slot, and the second axis is not connected to the first axis and the brake axis; the buckle is in the second slot, the second axis is connected to the brake axis, the buckle is not in the first slot and the second slot, and the first axis and the second axis are connected.
5. The cart for converting gravitational potential energy into kinetic energy according to claim 3, characterized in that: A second spring is sleeved on the lead screw.
6. The cart for converting gravitational potential energy into kinetic energy according to claim 4, characterized in that: The chassis is provided with a guide wheel for the steel wire rope, and the steel wire rope passes through the bottom of the guide wheel.