A stowed shipboard gantry crane

Abstract

The application discloses a retractable ship-mounted gantry crane device and relates to the technical field of gantry cranes. The device comprises a base, a fixing seat, a П-shaped hanger and an electric push rod, and further comprises a buffer assembly and a guide assembly. The buffer assembly is hingedly arranged on the П-shaped hanger. When the ship body shakes, the buffer assembly shakes in the opposite direction relative to the ship body. The guide assembly comprises wheel set one, wheel set two and wheel set three which are connected with each other and used for penetrating a traction rope. The wheel set one is arranged on the buffer assembly, the wheel set two is arranged between the wheel set one and the wheel set three, and the wheel set two moves downward when the wheel set one swings away from the wheel set three. In use, the buffer assembly and the guide assembly are matched, the instantaneous tension on the surface of the hoisted cable is reduced when the ship body shakes, and the cable is effectively protected.

Description

Technical Field

[0001] This invention relates to the field of gantry crane technology, and more specifically to a retractable shipborne gantry crane. Background Technology

[0002] A shipboard gantry crane, also known as a marine gantry crane or shipboard gantry crane, is a large lifting device with a structure resembling a "gate". It consists of a main beam, outriggers, a lifting trolley, a traveling mechanism, and an electrical system, and is capable of lifting and moving heavy objects on the deck or above the cargo hold of a ship.

[0003] Submarine cable maintenance is crucial for ensuring the normal operation of cables. However, conventional gantry cranes, fixed in ports and unable to move with ships, hinder cable lifting at different locations, significantly impacting maintenance work on submarine cables. While existing technologies offer solutions, such as installing gantry cranes at the stern of ships, allowing them to move with the vessel and lift cables from various positions on the sea surface for maintenance after prolonged use, several problems remain. In rough seas, ships experience six degrees of freedom of motion: pitching, swaying, heeling, rolling, pitching, and yaw. During cable lifting, this motion can lead to excessively high lifting speeds. Rapid lifting amplifies the instantaneous tensile stress caused by waves, causing cable tension far exceeding design values, particularly at the armor layer or joints, which are prone to breakage or internal damage. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention is proposed.

[0005] Therefore, the purpose of this invention is to provide a retractable shipborne gantry crane, which aims to solve the problem that in a turbulent marine environment, ships undergo six degrees of freedom of motion. During the lifting of cables, the lifting speed may be too fast due to the six degrees of freedom of motion. Rapid lifting will superimpose the instantaneous tensile peak caused by waves, causing the cable tension to far exceed the design value. In particular, the armor layer or joint area is prone to breakage or internal damage.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a retractable shipborne gantry crane, comprising a base, a fixed base, a P-shaped gantry crane, and an electric push rod. The base is fixedly mounted on the hull, the fixed base is fixedly mounted on the base, the lower end of the P-shaped gantry crane is hinged to the fixed base, and the two ends of the electric push rod are respectively hinged to the fixed base and the P-shaped gantry crane.

[0007] It also includes a buffer assembly and a guide assembly. The buffer assembly is hinged to the P-shaped gantry. When the hull sways, the buffer assembly sways in the opposite direction to the hull. The guide assembly includes three wheel sets connected to each other and used for threading a traction rope. The first wheel set is disposed on the buffer assembly, and the second wheel set is disposed between the first and third wheel sets. When the first wheel set swings with the buffer assembly and moves away from the third wheel set, the second wheel set moves downward.

[0008] As a preferred embodiment of the retractable shipborne gantry crane equipment of the present invention, the buffer assembly includes a hinge, a fixed rod, a hollow column, an annular plate, and a spring. The hinge is disposed on a P-shaped hanger, the fixed rod is disposed on the hinge, the hollow column is sleeved on the fixed rod, the annular plate is sleeved on the hollow column, the spring is disposed between the hinge and the annular plate and sleeved with the hollow column, and the first wheel assembly is disposed at the bottom of the annular plate.

[0009] As a preferred embodiment of the retractable shipborne gantry crane equipment of the present invention, the hinge component includes a fixing block, a sleeve, a U-shaped plate, a connecting block, and a connecting plate. The fixing block is disposed on the П-shaped hanger, the sleeve is sleeved on the fixing block, the U-shaped plate is disposed on the sleeve, the connecting block has a pin inside and is rotatably disposed inside the U-shaped plate through the pin, the central axis of the pin is perpendicular to the central axis of the sleeve, and the connecting plate is disposed at the bottom of the connecting block and connected to the upper end of the fixing rod.

[0010] As a preferred embodiment of the retractable shipborne gantry crane equipment of the present invention, the guiding assembly further includes an L-shaped telescopic rod and a U-shaped telescopic rod. The two ends of the L-shaped telescopic rod are respectively connected to the connecting block and the third wheel assembly. The two ends of the U-shaped telescopic rod are respectively connected to the first wheel assembly and the third wheel assembly. Two connecting rods are hinged on the second wheel assembly. Gears are fixedly installed at the upper ends of the two connecting rods. The two gears mesh with each other. The lower ends of the two connecting rods are respectively hinged to the first wheel assembly and the third wheel assembly.

[0011] As a preferred embodiment of the retractable shipborne gantry crane equipment of the present invention, wherein: a piston ring is sleeved inside the hollow column, the piston ring is mounted on a fixed rod, and a one-way valve one and a one-way valve two connected to the inside of the hollow column are provided on the annular plate, the one-way valve one being an air inlet valve and the one-way valve two being an air outlet valve.

[0012] In a preferred embodiment of the retractable shipborne gantry crane equipment described in this invention, the U-shaped telescopic rod is horizontal when the П-shaped gantry is stationary.

[0013] As a preferred embodiment of the retractable shipborne gantry crane equipment of the present invention, the number of one-way valves is greater than the number of two-way valves, and the sum of the conducting cross-sectional areas of the plurality of one-way valves is equal to the radial cross-sectional area of ​​the inner ring of the hollow column.

[0014] In a preferred embodiment of the retractable shipborne gantry crane equipment described in this invention, the maximum compression of the spring is 2 meters.

[0015] In summary, the present invention has at least one of the following beneficial effects:

[0016] 1. This invention, through the installation of an electric push rod and a buffer assembly, extends the P-shaped gantry to the outside of the hull when lifting submarine cables, and retracts the P-shaped gantry onto the hull when not performing lifting operations, thus preventing the ship's center of gravity from shifting. At the same time, when the hull sways vertically due to wind and waves on the sea surface, the buffer assembly can slow down the vertical movement speed of the first wheel assembly, preventing rapid changes in the tension on the surface of the traction rope threaded on the first wheel assembly. This reduces the instantaneous tension applied to the cable surface when lifting submarine cables, achieving effective protection for the cables.

[0017] 2. The present invention, through the provided hinge, can provide wheel set one with swing freedom in four directions (forward, backward, left, and right) while connecting wheel set one to the П-type gantry. Thus, when the hull sways due to waves, it can reduce the instantaneous tension applied to the surface of the submarine cable during lifting, and also allow wheel set one to act as a damper during swinging. This not only protects the cable, but also ensures the stability of the hull when waves are generated at sea.

[0018] 3. The present invention, through the setting of wheel set two, wheel set three, L-shaped telescopic rod and U-shaped telescopic rod, can reduce the height between wheel set two and wheel set one and wheel set three by using the centrifugal force and gravity generated by the swing when wheel set one swings around the horizontal section of the П-shaped gantry. This avoids the tension on the surface of the traction rope from increasing as wheel set one swings upward from the bottom, and achieves further protection for the lifting cable. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0021] Figure 2This is a schematic diagram of the connection structure of the П-type hanger, buffer assembly, and guide assembly of the present invention;

[0022] Figure 3 For the present invention Figure 2 A magnified structural diagram of part A;

[0023] Figure 4 This is a schematic diagram of the connection structure between wheel set one, wheel set two, and wheel set three of the present invention;

[0024] Figure 5 This is a schematic diagram of the connection structure between the П-type hanger and the wheel set of the present invention:

[0025] Figure 6 This is a diagram showing the state of the П-type hanger of the present invention during operation.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Base; 2. Fixed base; 3. П-type hanger; 4. Electric push rod; 5. Buffer assembly; 51. Hinge; 511. Fixed block; 512. Sleeve; 513. U-shaped plate; 514. Connecting block; 5141. Shaft pin; 515. Connecting plate; 52. Fixed rod; 53. Hollow column; 531. Piston ring; 532. One-way valve I; 533. One-way valve II; 54. Annular plate; 55. Spring; 6. Guide assembly; 61. Wheel set I; 62. Wheel set II; 621. Connecting rod; 622. Gear; 63. Wheel set III; 64. L-shaped telescopic rod; 65. U-shaped telescopic rod. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] This invention discloses a retractable shipborne gantry crane.

[0030] Example 1

[0031] Reference Figure 1-6This is the first embodiment of the present invention, which provides a retractable shipborne gantry crane. The retractable shipborne gantry crane includes a base 1, a fixed base 2, a П-shaped gantry crane 3, and an electric push rod 4. The base 1 is fixedly installed on the hull to ensure the stability of the base 1. The fixed base 2 is fixedly installed on the base 1. The lower end of the П-shaped gantry crane 3 is hinged to the fixed base 2. The two ends of the electric push rod 4 are respectively hinged to the fixed base 2 and the П-shaped gantry crane 3. By controlling the output length of the electric push rod 4, the angle of the П-shaped gantry crane 3 can be controlled so that it can be extended to the outside of the hull when in use and retracted to the hull when not in use.

[0032] It also includes a buffer assembly 5 and a guide assembly 6. The buffer assembly 5 is hinged on the П-shaped gantry 3. When the hull sways, the buffer assembly 5 sways in the opposite direction to the hull. The guide assembly 6 includes a first wheel set 61, a second wheel set 62, and a third wheel set 63 that are connected to each other and used to thread the traction rope. The first wheel set 61 is set on the buffer assembly 5, and the second wheel set 62 is set between the first wheel set 61 and the third wheel set 63. When the first wheel set 61 swings with the buffer assembly 5 and moves away from the third wheel set 63, the second wheel set 62 moves downward.

[0033] The buffer assembly 5 includes a hinge 51, a fixing rod 52, a hollow column 53, an annular plate 54, and a spring 55. The hinge 51 is mounted on the П-shaped hanger 3, the fixing rod 52 is mounted on the hinge 51, the hollow column 53 is sleeved on the fixing rod 52, the annular plate 54 is sleeved on the hollow column 53, the spring 55 is located between the hinge 51 and the annular plate 54 and is sleeved on the hollow column 53, and the wheel set 61 is located at the bottom of the annular plate 54.

[0034] It is known that existing ships typically equip themselves with a heave compensation system to reduce lifting tension on submarine cables during hoisting and maintenance, in order to avoid increased lifting tension due to hull swaying. However, the heave compensation system has high energy consumption and cost, and a malfunction of the system while the ship is at sea can prevent professionals from repairing it in a timely manner, affecting the maintenance of submarine cables. Therefore, this solution is adopted, which uses a fixed rod 52, a hollow column 53, and a spring 55 to reduce the lifting tension on the cables when the hull is swayed by waves. During the upward movement, under the gravity of the hollow column 53 and the guide component 6, the hollow column 53 cannot move upward synchronously with the П-type gantry 3, which has the effect of delayed upward movement. This prevents the traction rope threaded on the wheel set 61 from being immediately pulled by the instantaneous tension peak caused by the superimposed waves during rapid lifting, thereby reducing the traction tension of the traction rope on the submarine cable. Subsequently, it will be reset under the elastic force of the spring 55 to ensure the normal progress of the cable lifting operation. This ensures the smooth progress of the maintenance operation while also achieving effective protection of the cable.

[0035] The maximum compression of spring 55 is 2 meters. It can be seen that the size of the waves on the sea surface will determine the height of the ship's hull. On ships without a "heave compensation" system, a wave height of 3 meters can produce a lifting point heave of 1 to 2 meters. Therefore, the maximum compression of spring 55 of 2 meters enables the use of a gantry crane to lift and repair cables under a wave height of 3 meters.

[0036] The hinge 51 includes a fixing block 511, a sleeve 512, a U-shaped plate 513, a connecting block 514, and a connecting plate 515. The fixing block 511 is fixedly mounted on the П-shaped hanger 3. The sleeve 512 is rotatably mounted on the fixing block 511. The U-shaped plate 513 is fixedly mounted on the sleeve 512. When the hull sways, the sleeve 512 can rotate in two degrees of freedom, left and right. The connecting block 514 has a pivot pin 5141 inside and is rotatably mounted inside the U-shaped plate 513 through the pivot pin 5141. When the hull sways, the connecting block 514 can rotate in two degrees of freedom, forward and backward, under the action of the pivot pin 5141. This allows the fixed rod 52 to swing with four degrees of freedom. The central axis of the pivot pin 5141 is perpendicular to the central axis of the sleeve 512. The connecting plate 515 is located at the bottom of the connecting block 514 and connected to the upper end of the fixed rod 52. Through the hinge, the fixed rod 52 and the components connected to the fixed rod 52 can act as dampers during the swaying of the hull, which reduces the swaying effect of the hull to a certain extent and effectively ensures the stability of the hull. This ensures the stability of the cable when lifting the submarine cable, reduces the instantaneous tension applied to the surface of the cable during the lifting process, and achieves effective protection of the cable.

[0037] The guiding assembly 6 also includes an L-shaped telescopic rod 64 and a U-shaped telescopic rod 65. The two ends of the L-shaped telescopic rod 64 are connected to the connecting block 514 and the third wheel assembly 63, respectively. The two ends of the U-shaped telescopic rod 65 are connected to the first wheel assembly 61 and the third wheel assembly 63, respectively. The U-shaped telescopic rod 65 is an "L"-shaped extension rod, facilitating connection to the first wheel assembly 61 and the third wheel assembly 63 from the side. Simultaneously, the U-shaped telescopic rod 65 is an elastic telescopic rod. During the lifting of the submarine cable by the traction rope passing through the first wheel assembly 61, the second wheel assembly 62, and the third wheel assembly 63, the elasticity of the U-shaped telescopic rod 65 overcomes the surface tension of the traction rope, preventing changes in the distance between the first wheel assembly 61 and the third wheel assembly 63. Two connecting rods 6 are hinged on the second wheel assembly 62. 21. Gears 622 are fixedly installed at the upper ends of the two connecting rods 621. The two gears 622 mesh with each other. The lower ends of the two connecting rods 621 are hinged to wheel set one 61 and wheel set three 63 respectively. When the П-type gantry 3 is stationary, the U-shaped telescopic rod 65 is horizontal. During the process of the hull rocking causing the sleeve 512 to rotate around the fixed block 511 and drive wheel set one 61 to swing, the centrifugal force generated by the swing, the gravity of wheel set two 62 and wheel set three 63, and the tension of the traction rope will pull wheel set three 63 away from wheel set one 61. Under the meshing action of the connecting rods 621 and the two gears 622, wheel set two 62 will move downward, reducing the tension on the surface of the traction rope, thereby reducing the instantaneous pressure on the surface of the lifted cable when the traction rope contracts, and achieving further protection for the cable.

[0038] A piston ring 531 is fitted inside the hollow column 53 and is mounted on the fixed rod 52. A one-way valve 532 and a one-way valve 533, both communicating with the interior of the hollow column 53, are mounted on the annular plate 54. The one-way valve 532 is an intake valve, and the one-way valve 533 is an exhaust valve. The number of one-way valves 532 exceeds the number of one-way valves 533, and the sum of the conducting cross-sectional areas of the multiple one-way valves 532 equals the radial cross-sectional area of ​​the inner ring of the hollow column 53. When the hull moves relative to the fixed rod 52 due to the upward movement of waves, the piston ring 531 inside the hollow column 53 provides resistance, slowing the movement of the hollow column 53 relative to the fixed rod 52. The relative movement speed between them, and at the same time, during the process of the hollow column 53 moving downward relative to the piston ring 531 and stretching the spring 55, multiple one-way valves 532 can draw external air into the interior of the hollow column 53 under the action of air pressure difference. During the process of the spring 55 resetting, the hollow column 53 will move upward relative to the piston ring 531, and under the action of the one-way valve 533, the air inside the hollow column 53 will be discharged. This avoids the situation where the rapid deformation of the spring 55 when the hull is rocking causes the wheel set 61 to move rapidly along the axis of the fixed rod 52, thereby avoiding excessive instantaneous pressure changes on the cable when the cable is lifted, and achieving further protection for the cable.

[0039] When it is necessary to lift and repair submarine cables, start the electric push rod 4. The output end of the electric push rod 4 extends outward and drives the П-type gantry 3 to rotate around the hinge point with the fixed base 2, so that the П-type gantry 3 extends to the outside of the hull. After hooking the hook at the bottom of the traction rope to the submarine cable, the winch at the top of the hull is used to wind up the traction rope to lift the cable.

[0040] When the hull sways upward due to waves, wheel sets 61, 62, and 63 are slowed down by inertia, preventing the traction rope on wheel set 61 from being subjected to strong traction and increasing the instantaneous tension on the surface of the lifting cable. As the hull moves upward, the П-shaped gantry 3 moves synchronously upward with the base 1 under the action of the fixed seat 2. Since the fixing block 511 is set on the П-shaped gantry 3 and sleeved with the sleeve 512, the sleeve 512 can also move synchronously upward with the hull. During the process of the sleeve 512 moving synchronously upward with the hull, the fixing rod 52 will be affected by the hinge. 51 moves upward synchronously with the sleeve 512, causing the piston ring 531 on the fixed rod 52 to move upward relative to the hollow column 53. During the upward movement of the piston ring 531, external air will enter the interior of the hollow column 53 through multiple one-way valves 532 under the action of air pressure difference. This ensures that the fixed rod 52 and the hollow column 53 can move relative to each other, while increasing the resistance when they move relative to each other. This prevents the instantaneous pressure applied to the cable by the traction rope from changing too much. This can protect the cable and also prevent the cable from being unable to be effectively lifted due to a rapid drop in instantaneous pressure.

[0041] When the hull sways horizontally due to waves, the hinge 51 provides four degrees of freedom (forward, backward, left, and right) for the first wheel assembly 61 in the horizontal direction. This allows the first wheel assembly 61 to act as a damper during the swing, improving the stability of the hull. Simultaneously, during the swing, it can use centrifugal force and gravity to overcome the elastic force of the U-shaped telescopic rod 65, causing the first wheel assembly 61 and the third wheel assembly 63 to move away from each other. Furthermore, during the movement of the first wheel assembly 61 and the third wheel assembly 63 away from each other, the meshing connection of the two gears 622 causes the second wheel assembly 62 to move downward. That is, during the upward swing of the first wheel assembly 61 at its lowest point, the height of the second wheel assembly 62 is reduced, thereby reducing the tension on the surface of the traction rope passing through the first wheel assembly 61, the second wheel assembly 62, and the third wheel assembly 63. This further reduces the instantaneous tension on the cable surface caused by the traction rope during the lifting process, achieving further protection for the cable.

[0042] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A retractable shipborne gantry crane, comprising a base (1), a fixed base (2), a П-shaped lifting frame (3), and an electric push rod (4), characterized in that: It also includes a buffer assembly (5) and a guide assembly (6). The buffer assembly (5) is hinged on the П-shaped gantry (3). When the hull sways, the buffer assembly (5) sways in the opposite direction relative to the hull. The guide assembly (6) includes a wheel set one (61), a wheel set two (62), and a wheel set three (63) that are connected to each other and used to thread the traction rope. The wheel set one (61) is set on the buffer assembly (5). The wheel set two (62) is set between the wheel set one (61) and the wheel set three (63). When the wheel set one (61) swings with the buffer assembly (5) and moves away from the wheel set three (63), the wheel set two (62) moves downward. The buffer assembly (5) includes a hinge (51), a fixing rod (52), a hollow column (53), an annular plate (54), and a spring (55). The hinge (51) is mounted on the П-shaped hanger (3), the fixing rod (52) is mounted on the hinge (51), the hollow column (53) is sleeved on the fixing rod (52), the annular plate (54) is sleeved on the hollow column (53), the spring (55) is located between the hinge (51) and the annular plate (54) and is sleeved on the hollow column (53). The first wheel assembly (61) is located at the bottom of the annular plate (54). The hinge (51) includes a fixing block (511), a sleeve (512), a U-shaped plate (513), a connecting block (514), and a connecting plate (515). The fixing block (511) is mounted on the П-shaped hanger (3). The sleeve (512) is fitted onto the fixing block (511). The U-shaped plate (513) is mounted on the sleeve (512). The connecting block (514) has a shaft pin (5141) inside and is rotatably mounted inside the U-shaped plate (513) through the shaft pin (5141). The central axis of the shaft pin (5141) is perpendicular to the central axis of the sleeve (512). The connecting plate (515) is located at the bottom of the connecting block (514) and connected to the upper end of the fixing rod (52). The guide assembly (6) further includes an L-shaped telescopic rod (64) and a U-shaped telescopic rod (65). The two ends of the L-shaped telescopic rod (64) are connected to the connecting block (514) and the wheel set three (63) respectively. The two ends of the U-shaped telescopic rod (65) are connected to the wheel set one (61) and the wheel set three (63) respectively. Two connecting rods (621) are hinged on the wheel set two (62). Gears (622) are fixedly provided at the upper ends of the two connecting rods (621). The two gears (622) mesh with each other. The lower ends of the two connecting rods (621) are hinged to the wheel set one (61) and the wheel set three (63) respectively. The U-shaped telescopic rod (65) is an elastic telescopic rod. During the process of lifting the submarine cable by passing through wheel set one (61), wheel set two (62) and wheel set three (63), the elastic effect of the U-shaped telescopic rod (65) is used to overcome the tension on the surface of the traction rope.

2. The retractable shipborne gantry crane equipment according to claim 1, characterized in that, A piston ring (531) is fitted inside the hollow column (53). The piston ring (531) is mounted on the fixed rod (52). A one-way valve (532) and a one-way valve (533) connected to the inside of the hollow column (53) are provided on the annular plate (54). The one-way valve (532) is an intake valve, and the one-way valve (533) is an exhaust valve.

3. The retractable shipborne gantry crane equipment according to claim 1, characterized in that, When the П-type hanger (3) is stationary, the U-shaped telescopic rod (65) is horizontal.

4. The retractable shipborne gantry crane equipment according to claim 2, characterized in that, The number of one-way valves (532) is greater than the number of one-way valves (533), and the sum of the conducting cross-sectional areas of the multiple one-way valves (532) is equal to the radial cross-sectional area of ​​the inner ring of the hollow column (53).

5. The retractable shipborne gantry crane equipment according to claim 1, characterized in that, The maximum compression of the spring (55) is 2 meters.

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