A movable pulley assembly for lifting underwater pumps and its usage method

Abstract

This invention discloses a movable pulley assembly for lifting underwater pumps, belonging to the field of marine equipment technology. The movable pulley assembly for lifting underwater pumps includes a pulley frame and a pulley body, which is mounted on the pulley frame via a pulley axle. A connecting device includes a rotating shaft rotatably connected to the pulley frame, a large nut threaded to the top of the rotating shaft, and a cross joint at the bottom of the rotating shaft for connecting the pulley frame to an external fixing frame. The pulley frame is a box-shaped structure welded from two side plates, an upper end plate, and a lower end plate. Reinforcing ribs are provided on the outer sides of the two side plates of the pulley frame. The pulley axle of the pulley body is located on the side plates, and a lifting lug is provided on the top of the upper end plate of the pulley frame. The sealing structure of this invention extends the lifespan of the pulley assembly in marine environments by more than 30%, reduces failures caused by seawater erosion and silt abrasion, and the fully enclosed lubrication system completely eliminates the possibility of grease leakage polluting the ocean.

Description

Technical Field

[0001] This invention relates to the field of marine equipment technology, and in particular to a dynamic pulley assembly for lifting underwater pumps and its method of use. Background Technology

[0002] Submersible pumps are core equipment in dredging operations and underwater engineering. Their installation, maintenance, and retrieval typically rely on pulley systems for efficient and stable hoisting. As a key component of the lifting mechanism, the performance of the pulley system directly affects the safety, reliability, and service life of the submersible pump.

[0003] Due to the harsh working conditions of underwater operations, such as seawater corrosion and silt abrasion, traditional pulley assemblies are prone to premature failure due to material corrosion and structural wear, resulting in a significantly shortened service life. Traditional pulley bearings have poor sealing performance and lack effective grease drainage structures, which can easily cause grease leakage and lead to marine environmental pollution. The replacement and maintenance process of pulley bearings is complex, requiring the disassembly of a large number of parts, which increases maintenance costs and safety risks. Affected by factors such as operating water depth, hoisting angle, and installation errors, existing pulley systems are prone to jamming and uneven loading during operation, which seriously affects operational safety. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art, and to propose a dynamic pulley assembly for lifting underwater pumps and its usage method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A movable pulley assembly for lifting an underwater pump includes a pulley frame and further includes:

[0007] A pulley body, which is mounted on a pulley frame via a pulley axle;

[0008] A connecting device, comprising a rotating shaft rotatably connected to the pulley frame, a large nut threadedly connected to the top of the rotating shaft, and a cross joint located at the bottom of the rotating shaft, for connecting the pulley frame to an external fixed frame;

[0009] The pulley frame is a box-shaped structure welded together from two side plates, an upper end plate, and a lower end plate. Reinforcing ribs are provided on the outer sides of the two side plates of the pulley frame. The pulley axle of the pulley body is located on the side plates. A lifting lug is provided on the top of the upper end plate of the pulley frame.

[0010] Preferably, the side plate of the pulley frame has a shaft hole for the rotation of the pulley shaft, a first O-ring for static sealing is provided in the shaft hole, a stainless steel liner is provided on the outer wall of the side plate at the shaft hole, and a plurality of anti-jump cables are provided on the side plate circumferentially with the shaft hole as the center.

[0011] Preferably, the pulley body includes a bushing sleeve fitted on the outside of the pulley shaft, a pulley body fixed on the outside of the bushing sleeve, a mounting plate bolted to the outside of the pulley body, and two sets of first V-shaped oil seals disposed in the mounting plate. The first V-shaped oil seals form a dynamic seal with the stainless steel liner. The pulley body also includes a first retaining plate fixed on the pulley shaft and moving against the first O-ring.

[0012] Preferably, the connecting device further includes a pad, a sealing device, a pin, and a second retaining plate;

[0013] The pad is disposed between the large nut and the lower end plate. The large nut is a cap-shaped piece, and the rotating shaft is fixed to the upper side of the lower end plate of the pulley frame by threads.

[0014] The pin is located on the lower side of the rotating shaft and is connected to the second retaining plate, used to connect the rotating shaft and the cross joint;

[0015] The sealing device is installed between the rotating shaft and the lower end plate to seal the rotational fit clearance between the rotating shaft and the lower end plate.

[0016] Preferably, the sealing device includes a lower cover, a sealing gasket, a second V-shaped oil seal, a second O-ring, and two upper covers;

[0017] The two upper covers are fixed to the upper edge of the lower end plate of the pulley frame by bolts, and the sealing gasket is provided on the mating surface between the upper cover and the lower end plate;

[0018] The lower cover is fixed to the lower edge of the lower end plate by bolts. The second O-ring is disposed on the upper end face of the lower cover and moves against the bottom wall of the lower end plate. The second V-shaped oil seal is disposed on the inner side wall of the lower cover and moves against the rotating shaft.

[0019] Preferably, both the lower end plate and the pulley shaft are provided with oil injection ports for injecting new grease into the sealed cavity between the pulley shaft and the bushing and / or between the rotating shaft and the lower end plate;

[0020] Both the mounting plate and the lower cover are provided with oil drain ports to drain old grease from the sealed cavities between the pulley shaft and the bushing and / or between the rotating shaft and the lower end plate.

[0021] Both the oil inlet and outlet are equipped with plugs.

[0022] Preferably, a paint marking line is provided at the boundary between the rotating shaft and the lower cover of the sealing device for visual observation of the wear condition of the pad.

[0023] Preferably, the pulley frame has reserved installation interfaces at all four corners of its side plate for installing maintenance brackets.

[0024] Preferably, the lower part of the cross joint is rotatably connected to the external fixing frame via a shaft, which is used to realize multi-angle adjustment of the pulley frame in the horizontal and vertical directions during hoisting operations. The external fixing frame is also provided with an auxiliary installation interface, and the maintenance bracket is set between the reserved installation interface and the auxiliary installation interface.

[0025] The present invention also discloses a method of using a movable pulley assembly for lifting an underwater pump, which further includes the following steps:

[0026] S1: Install the entire pulley assembly onto the lifting system of the engineering vessel. The lifting lugs on the top of the pulley frame are used to assist in the installation or as auxiliary lifting points. The cross joint at the bottom of the connecting device is pinned to the external fixing frame.

[0027] S2: When the underwater pump is raised or lowered, the direction of force on the wire rope will dynamically change due to water flow, hull tilt, or installation errors. At this time, the connection device will automatically adjust:

[0028] First adjustment: The pivot is connected to the cross joint through the pin at its lower part, allowing the pulley frame to swing within a certain angle range in the vertical plane;

[0029] Second adjustment: The top of the pivot forms a rotating pair with the lower end plate of the pulley frame through a large nut and a washer, allowing the pulley frame to rotate around the pivot in the horizontal plane;

[0030] The third adjustment: the cross joint is pinned to the external fixing frame, allowing the connecting device to rotate and swing relative to the external fixing frame around the shaft connection point.

[0031] The combination of multiple degrees of freedom adjustment makes the pulley assembly a "universal" joint, which can adapt to the tension direction of the wire rope in real time, ensuring that the pulley groove always maintains the best alignment with the wire rope, and completely avoiding off-center loading and jamming.

[0032] S3: When the pulley body rotates, the first V-shaped oil seals on both sides of the pulley body fit tightly with the stainless steel liner plate welded on the side plate, forming a dynamic sealing barrier, which effectively prevents seawater and mud from entering the bearing cavity, and at the same time prevents the internal grease from leaking out.

[0033] A static seal is achieved between the pulley shaft and the shaft hole of the pulley frame side plate through a first O-ring;

[0034] The sealing device completely encloses the upper dynamic connection of the large nut and the shaft, forming an independent sealed cavity. The upper cover is statically sealed to the lower end plate through the sealing gasket, while the lower cover achieves dynamic sealing of the shaft through the second V-type oil seal and the second O-ring.

[0035] S4: When the grease needs to be replaced, the maintenance personnel do not need to disassemble any parts. They can simply add new grease into the sealed cavity through the oil inlet on the lower end plate or pulley shaft. Under pressure, the old grease will be squeezed out from the corresponding oil outlet. After the new grease overflows, the oil outlet can be sealed with a plug to complete the replacement.

[0036] S5: At the boundary between the shaft and the lower cover, there is a yellow paint marking line. As the pad wears, the shaft moves relative to the lower end plate, causing the paint marking line to move down. By observing the change in the position of the paint marking line, maintenance personnel can intuitively judge the wear degree of the pad, realize predictive maintenance, and avoid equipment failure due to excessive wear.

[0037] S6: During major maintenance, the maintenance bracket is installed through the reserved installation interfaces at the four corners of the side plate. The other end of the maintenance bracket is fixed to the auxiliary installation interface of the external fixing frame, which rigidly fixes the entire pulley assembly, providing a stable and safe working platform for the operators and preventing the pulley assembly from accidentally rotating or tipping over during maintenance.

[0038] Compared with the prior art, the present invention provides a moving pulley assembly for lifting underwater pumps and its method of use, which has the following beneficial effects:

[0039] 1. In this invention, the box-type welded pulley frame and the lower end plate of the forging provide extremely high structural rigidity and strength; the multi-stage sealing system (O-ring static seal, V-type oil seal dynamic seal, and overall sealing device seal) effectively resists seawater erosion and silt wear, significantly extending the service life of the components.

[0040] 2. In this invention, the multi-adaptive adjustment mechanism based on cross joints and rotating shafts can automatically compensate for hoisting angles and installation errors, eliminate off-center loading and jamming, ensure the stability and safety of underwater pump lifting operations, solve the problem of frequently adjusting pulley block angles during underwater hoisting in the prior art, reduce the difficulty of operation, and improve construction efficiency.

[0041] 3. In this invention, the fully enclosed lubrication system completely eliminates the possibility of grease leakage and marine pollution. Furthermore, the design of the oil filling port / oil unloading port allows for grease replacement without disassembly, achieving "maintenance without opening the cover" and solving the problem that traditional pulley assemblies require disassembly of the entire structure for lubrication maintenance.

[0042] 4. In this invention, by setting paint marking lines, visual wear indicators can be provided, helping staff to intuitively observe the wear of the gaskets and effectively prevent sudden failures. Furthermore, the reserved installation interface and auxiliary installation interface facilitate the use of maintenance brackets to rigidly fix the entire pulley assembly during maintenance, preventing the pulley assembly from shaking arbitrarily due to the universal adjustment of the shaft and cross joint, and preventing the pulley assembly from accidentally rotating or tipping over during maintenance. This greatly improves the efficiency and safety of maintenance operations and reduces the total life cycle cost. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0044] Figure 2 This is a schematic diagram of the connection structure between the pulley frame and the maintenance bracket of the present invention;

[0045] Figure 3 for Figure 2 The front view;

[0046] Figure 4 for Figure 3 A magnified structural diagram of part A in the diagram;

[0047] Figure 5 for Figure 2 The left view;

[0048] Figure 6 for Figure 5 A schematic diagram of the cross-sectional structure;

[0049] Figure 7 for Figure 6 Enlarged structural diagram of section B in the middle;

[0050] Figure 8 for Figure 6 Enlarged structural diagram of section C;

[0051] Figure 9 for Figure 3 A schematic diagram of the cross-sectional structure;

[0052] Figure 10 for Figure 9 Enlarged structural diagram of section D in the middle;

[0053] Figure 11 This is a cross-sectional structural diagram of the pulley frame of the present invention;

[0054] Figure 12 This is a schematic diagram of the sealing device and rotating shaft of the present invention.

[0055] In the diagram: 1. Pulley frame; 101. Side plate; 102. Upper end plate; 103. Lower end plate; 104. Lifting lug; 105. Reinforcing rib plate; 106. Anti-slip cable rod; 107. Stainless steel liner plate; 108. First O-ring; 2. Pulley body; 201. Pulley body; 202. Bushing; 203. Pulley shaft; 204. First retaining plate; 205. Mounting plate; 206. First V-type oil seal; 3. Connecting device; 301. Large nut; 302 1. Shaft; 303. Pad; 304. Sealing device; 3041. Top cover; 3042. Second O-ring; 3043. Bottom cover; 3044. Sealing gasket; 3045. Second V-type oil seal; 305. Cross joint; 306. Pin; 307. Second shaft retaining plate; 5. External fixing bracket; 501. Auxiliary installation interface; 6. Oil inlet; 7. Oil outlet; 8. Paint marking line; 9. Reserved installation interface; 10. Maintenance bracket; 11. Plug. Detailed Implementation

[0056] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0057] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0058] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0059] like Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 6As shown, this embodiment proposes a movable pulley assembly for lifting an underwater pump, including a pulley frame 1, a pulley body 2, and a connecting device 3; the pulley body 2 is mounted on the pulley frame 1 via a pulley shaft 203; the connecting device 3 includes a rotating shaft 302 rotatably connected to the pulley frame 1, a large nut 301 threadedly connected to the top of the rotating shaft 302, and a cross joint 305 located at the bottom of the rotating shaft 302, for connecting the pulley frame 1 to an external fixing frame 5; wherein, the pulley frame 1 consists of two side plates 1 01. A box-shaped structure is formed by welding the upper end plate 102 and the lower end plate 103. The lower end plate 103 is made of forging. The two side plates 101 of the pulley frame 1 are provided with reinforcing ribs 105 on their outer sides. The reinforcing ribs 105 increase the structural rigidity of the pulley frame 1. The pulley shaft 203 of the pulley body 2 is set on the side plate 101. The top of the upper end plate 102 of the pulley frame 1 is provided with lifting lugs 104. Two sets of lifting lugs 104 are welded to the upper end plate 102 for hoisting operations during the installation of the pulley assembly.

[0060] like Figure 6 , Figure 7 and Figure 11 As shown, in a preferred embodiment, based on the above method, the side plate 101 of the pulley frame 1 is further provided with a shaft hole for the rotation of the pulley shaft 203. A first O-ring 108 is provided in the shaft hole to achieve static sealing and ensure that seawater does not enter the inner cavity. A stainless steel liner 107 is provided on the outer wall of the side plate 101 at the shaft hole. Several anti-slip cable rods 106 are provided on the side plate 101 circumferentially with the shaft hole as the center to ensure that the wire rope does not jump out of the groove during operation.

[0061] like Figure 6 , Figure 7 and Figure 11 As shown, in a preferred embodiment, based on the above method, the pulley body 2 further includes a bushing 202 sleeved on the outside of the pulley shaft 203, a pulley body 201 fixed on the outside of the bushing 202, a mounting plate 205 bolted to the outside of the pulley body 201, and two sets of first V-shaped oil seals 206 disposed within the mounting plate 205. The bushing 202 and the pulley body 201 are assembled together and then installed on the pulley shaft 203. The first V-shaped oil seals 206 and the stainless steel liner 107 form a dynamic seal to ensure that seawater will not enter the inner cavity when the pulley rotates, and at the same time prevent the lubricating grease in the inner cavity from leaking out and polluting the ocean. The pulley body 2 also includes a first retaining plate 204 fixed on the pulley shaft 203 and movingly abutting against the first O-ring 108. The pulley shaft 203 is installed on the two side plates 101 of the pulley frame 1 and fixed by the first retaining plate 204.

[0062] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 6 , Figure 8 , Figure 9 and Figure 10 As shown, in a preferred embodiment, based on the above method, the connecting device 3 further includes a pad 303, a sealing device 304, a pin 306, and a second retaining plate 307.

[0063] The pad 303 is disposed between the large nut 301 and the lower end plate 103. The large nut 301 is a pressure cap shape, which increases the force-bearing area and improves the force distribution. The rotating shaft 302 is fixed to the upper side of the lower end plate 103 of the pulley frame 1 by threads. A pin can be provided between the large nut 301 and the rotating shaft 302 to ensure that the large nut 301 and the rotating shaft 302 are locked firmly.

[0064] The pin 306 is located on the lower side of the rotating shaft 302 and connected to the second retaining plate 307. It is used to connect the rotating shaft 302 and the cross joint 305. The lower part of the rotating shaft 302 is fixed to the cross joint 305 by the pin 306 and the second retaining plate 307. Through the structural design of the cross joint 305, the pulley has a degree of freedom similar to a universal joint. During hoisting operations, the pulley block can achieve adaptive angle adjustment under different working water depths, installation angles, and hoisting errors, solving the jamming and off-center load problems of the original structure.

[0065] The sealing device 304 is disposed between the rotating shaft 302 and the lower end plate 103 to seal the rotational fit clearance between the rotating shaft 302 and the lower end plate 103.

[0066] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 6 , Figure 8 , Figure 9 , Figure 10 and Figure 12 As shown, in a preferred embodiment, based on the above method, the sealing device 304 further includes a lower cover 3043, a sealing gasket 3044, a second V-shaped oil seal 3045, a second O-ring 3042, and two upper covers 3041.

[0067] The two upper covers 3041 are fixed to the upper edge of the lower end plate 103 of the pulley frame 1 by bolts, and the sealing gasket 3044 is set on the mating surface of the upper cover 3041 and the lower end plate 103, thereby ensuring that the upper structure of the large nut 301 and the rotating shaft 302 is isolated from seawater.

[0068] The lower cover 3043 is fixed to the lower edge of the lower end plate 103 by bolts. The second O-ring 3042 is set on the upper end face of the lower cover 3043 and moves against the bottom wall of the lower end plate 103. The second V-shaped oil seal 3045 is set on the inner side wall of the lower cover 3043 and moves against the rotating shaft 302, ensuring that the lower structure of the rotating shaft 302 is isolated from seawater.

[0069] like Figure 1 , Figure 2 , Figure 9 and Figure 10 As shown, in a preferred embodiment, based on the above method, both the lower end plate 103 and the pulley shaft 203 are provided with oil injection ports 6 for injecting new grease into the sealed cavity between the pulley shaft 203 and the bushing 202 and / or between the rotating shaft 302 and the lower end plate 103.

[0070] Both the mounting plate 205 and the lower cover 3043 are provided with oil discharge ports 7, which are used to discharge old grease from the sealed cavities between the pulley shaft 203 and the bushing 202 and / or between the rotating shaft 302 and the lower end plate 103.

[0071] Both the oil inlet 6 and the oil outlet 7 are equipped with plugs 11;

[0072] New grease enters the sealing cavity formed by the sealing device 304, lower end plate 103, and rotating shaft 302 through the oil inlet 6, or the sealing cavity formed by the mounting plate 205, bushing 202, and first V-type oil seal 206. At the same time, old grease is discharged from the sealing cavity through the oil outlet 7. Finally, the oil outlet 7 is plugged with the plug 11. The entire process does not require maintenance personnel to disassemble the sealing structure, making it safe, simple, and efficient.

[0073] like Figure 3 and Figure 4 As shown, in a preferred embodiment, based on the above method, a yellow paint marking line 8 is provided at the boundary between the rotating shaft 302 and the lower cover 3043 of the sealing device 304 for visual observation of the wear condition of the pad 303. When the pad 303 wears down after working for a period of time, the paint marking line 8 will drop, and maintenance personnel can directly observe the wear condition of the pad 303 visually, thereby making an advance judgment on whether maintenance and replacement are needed, and avoiding damage during operation.

[0074] like Figure 2 , Figure 3 , Figure 5 and Figure 6 As shown, in a preferred embodiment, based on the above method, the pulley frame 1 is further provided with reserved installation interfaces 9 at the four corners of the side plate 101 for installing the maintenance bracket 10.

[0075] Furthermore, the lower part of the cross joint 305 is rotatably connected to the external fixed frame 5 via a shaft, which is used to realize multi-angle adjustment of the pulley frame 1 in the horizontal and vertical directions during hoisting operations. The external fixed frame 5 is also provided with an auxiliary installation interface 501, and the maintenance bracket 10 is set between the reserved installation interface 9 and the auxiliary installation interface 501.

[0076] Specifically, during major maintenance, maintenance brackets 10 are installed through the reserved installation interfaces 9 at the four corners of the side plate 101. The other end of the maintenance bracket 10 is fixed to the auxiliary installation interface 501 of the external fixing frame 5, which rigidly fixes the entire pulley assembly, providing a stable and safe working platform for the operators, preventing the pulley assembly from accidentally rotating or tipping over during maintenance, and facilitating safe operation for the operators.

[0077] The present invention also discloses a method of using a movable pulley assembly for lifting an underwater pump, which further includes the following steps:

[0078] S1: Install the entire pulley assembly onto the lifting system of the engineering vessel. The lifting lug 104 on the top of the pulley frame 1 is used to assist in the installation or as an auxiliary lifting point. The cross joint 305 at the bottom of the connecting device 3 is pinned to the external fixing frame 5.

[0079] S2: When the underwater pump is raised or lowered, the direction of force on the wire rope will dynamically change due to water flow, hull tilt, or installation errors. At this time, the connecting device 3 will automatically change:

[0080] First adjustment: The rotating shaft 302 is connected to the cross joint 305 through the pin 306 at its lower part, allowing the pulley frame 1 to swing within a certain angle range in the vertical plane;

[0081] Second adjustment: The top of the rotating shaft 302 forms a rotating pair with the lower end plate 103 of the pulley frame 1 through the large nut 301 and the pad 303, allowing the pulley frame 1 to rotate around the rotating shaft 302 in the horizontal plane;

[0082] The third adjustment: the cross joint 305 is pinned to the external fixing frame 5, so that the connecting device 3 can rotate and swing relative to the external fixing frame 5 with the shaft connection point as the center.

[0083] The combination of multiple degrees of freedom adjustment makes the pulley assembly a "universal" joint, which can adapt to the tension direction of the wire rope in real time, ensuring that the pulley groove always maintains the best alignment with the wire rope, and completely avoiding off-center loading and jamming.

[0084] S3: When the pulley body 2 rotates, the first V-shaped oil seals 206 on both sides of the pulley body 2 are tightly fitted with the stainless steel liner 107 welded on the side plate 101 to form a main dynamic sealing barrier, which effectively prevents seawater and mud from entering the bearing cavity, and at the same time prevents the internal grease from leaking out.

[0085] A static seal is achieved between the pulley shaft 203 and the shaft hole of the side plate 101 of the pulley frame 1 through the first O-ring 108;

[0086] The sealing device 304 completely encloses the upper dynamic connection of the large nut 301 and the rotating shaft 302, forming an independent sealing cavity. The upper cover 3041 is statically sealed to the lower end plate 103 through the sealing gasket 3044, while the lower cover 3043 achieves dynamic sealing of the rotating shaft 302 through the second V-type oil seal 3045 and the second O-ring 3042.

[0087] S4: When the grease needs to be replaced, the maintenance personnel do not need to disassemble any parts. They can simply add new grease into the sealed cavity through the oil inlet 6 on the lower end plate 103 or pulley shaft 203. Under pressure, the old grease will be squeezed out from the corresponding oil outlet 7. After the new grease overflows, the oil outlet 7 can be sealed with the plug 11 to complete the replacement.

[0088] S5: At the boundary between the rotating shaft 302 and the lower cover 3043, there is a yellow paint marking line 8. As the pad 303 wears, the rotating shaft 302 moves relative to the lower end plate 103, causing the paint marking line 8 to move downward. By observing the change in the position of the paint marking line 8, maintenance personnel can intuitively judge the wear degree of the pad 303, realize predictive maintenance, and avoid equipment failure due to excessive wear.

[0089] S6: During major maintenance, the maintenance bracket 10 is installed through the reserved installation interfaces 9 at the four corners of the side plate 101. The other end of the maintenance bracket 10 is fixed to the auxiliary installation interface 501 of the external fixing frame 5, which rigidly fixes the entire pulley assembly, providing a stable and safe working platform for the operators and preventing the pulley assembly from accidentally rotating or tipping over during maintenance.

[0090] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0091] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A movable pulley assembly for lifting an underwater pump, comprising a pulley frame (1), characterized in that, Also includes: Pulley body (2), which is mounted on pulley frame (1) via pulley shaft (203); The connecting device (3) includes a rotating shaft (302) rotatably connected to the pulley frame (1), a large nut (301) threadedly connected to the top of the rotating shaft (302), and a cross joint (305) set at the bottom of the rotating shaft (302) for connecting the pulley frame (1) and the external fixing frame (5). The pulley frame (1) is a box-shaped structure welded from two side plates (101), an upper end plate (102) and a lower end plate (103). The two side plates (101) of the pulley frame (1) are provided with reinforcing ribs (105) on the outside. The pulley shaft (203) of the pulley body (2) is provided on the side plate (101). The upper end plate (102) of the pulley frame (1) is provided with a lifting lug (104) on top. The connecting device (3) also includes a pad (303), a sealing device (304), a pin (306), and a second retaining plate (307). The pad (303) is disposed between the large nut (301) and the lower end plate (103). The large nut (301) is a pressure cap, and the rotating shaft (302) is fixed to the upper side of the lower end plate (103) of the pulley frame (1) by threads. The pin (306) is located on the lower side of the rotating shaft (302) and connected to the second retaining plate (307), and is used to connect the rotating shaft (302) and the cross joint (305). The sealing device (304) is disposed between the rotating shaft (302) and the lower end plate (103) to seal the rotational fit clearance between the rotating shaft (302) and the lower end plate (103); The sealing device (304) includes a lower cover (3043), a sealing gasket (3044), a second V-type oil seal (3045), a second O-ring (3042), and two upper covers (3041). The two upper covers (3041) are fixed to the upper edge of the lower end plate (103) of the pulley frame (1) by bolts, and the sealing gasket (3044) is provided on the mating surface between the upper cover (3041) and the lower end plate (103); The lower cover (3043) is fixed to the lower edge of the lower end plate (103) by bolts. The second O-ring (3042) is disposed on the upper end face of the lower cover (3043) and moves against the bottom wall of the lower end plate (103). The second V-shaped oil seal (3045) is disposed on the inner side wall of the lower cover (3043) and moves against the rotating shaft (302).

2. The underwater pump lifting pulley assembly according to claim 1, characterized in that, The side plate (101) of the pulley frame (1) is provided with a shaft hole for the rotation of the pulley shaft (203). A first O-ring (108) for static sealing is provided in the shaft hole. A stainless steel liner (107) is provided on the outer wall of the side plate (101) at the shaft hole. Several anti-jumping cables (106) are provided on the side plate (101) circumferentially with the shaft hole as the center.

3. The underwater pump lifting pulley assembly according to claim 2, characterized in that, The pulley body (2) includes a bushing (202) sleeved on the outside of the pulley shaft (203), a pulley body (201) fixed on the outside of the bushing (202), a mounting plate (205) bolted on the outside of the pulley body (201), and two sets of first V-type oil seals (206) installed in the mounting plate (205). The first V-type oil seals (206) form a dynamic seal with the stainless steel liner (107). The pulley body (2) also includes a first retaining plate (204) fixed on the pulley shaft (203) and movingly abutting against the first O-ring (108).

4. The underwater pump lifting pulley assembly according to claim 3, characterized in that, Both the lower end plate (103) and the pulley shaft (203) are provided with oil injection ports (6) for injecting new grease into the sealed cavity between the pulley shaft (203) and the bushing (202) and / or between the rotating shaft (302) and the lower end plate (103); Both the mounting plate (205) and the lower cover (3043) are provided with oil discharge ports (7) for discharging old grease from the sealed cavity between the pulley shaft (203) and the bushing (202) and / or between the rotating shaft (302) and the lower end plate (103); Both the oil inlet (6) and the oil outlet (7) are equipped with plugs (11).

5. The underwater pump lifting pulley assembly according to claim 4, characterized in that, A paint marking line (8) is provided at the boundary between the rotating shaft (302) and the lower cover (3043) of the sealing device (304) for visual observation of the wear condition of the pad (303).

6. The underwater pump lifting pulley assembly according to claim 5, characterized in that, The pulley frame (1) has reserved installation interfaces (9) at the four corners of the side plate (101) for installing maintenance brackets (10).

7. The underwater pump lifting pulley assembly according to claim 6, characterized in that, The lower part of the cross joint (305) is rotatably connected to the external fixing frame (5) via a shaft, which is used to realize the multi-angle adjustment of the pulley frame (1) in the horizontal and vertical directions during the hoisting operation. The external fixing frame (5) is also provided with an auxiliary installation interface (501). The maintenance bracket (10) is set between the reserved installation interface (9) and the auxiliary installation interface (501).

8. A method of using the underwater pump lifting pulley assembly according to claim 7, characterized in that, It also includes the following steps: S1: Install the entire pulley assembly onto the lifting system of the engineering vessel. The lifting lug (104) on the top of the pulley frame (1) is used to assist in the installation or as an auxiliary lifting point. The cross joint (305) at the bottom of the connecting device (3) is pinned to the external fixing frame (5). S2: When the underwater pump is raised or lowered, the direction of force on the wire rope will change dynamically due to water flow, hull tilt, or installation error. At this time, the connecting device (3) will automatically change: First adjustment: The pivot (302) is connected to the cross joint (305) through the pin (306) at its lower part, allowing the pulley frame (1) to swing within a certain angle range in the vertical plane; Second adjustment: The top of the pivot (302) forms a rotating pair with the lower end plate (103) of the pulley frame (1) through the large nut (301) and the pad (303), allowing the pulley frame (1) to rotate around the pivot (302) in the horizontal plane; Third adjustment: The cross joint (305) is pinned to the external fixing frame (5), so that the connecting device (3) can rotate and swing relative to the external fixing frame (5) with the shaft connection as the center. The combination of multiple degrees of freedom adjustment makes the pulley assembly a "universal" joint, which can adapt to the tension direction of the wire rope in real time, ensuring that the pulley groove always maintains the best alignment with the wire rope, and completely avoiding off-center loading and jamming. S3: When the pulley body (2) rotates, the first V-shaped oil seals (206) on both sides of the pulley body (2) are tightly fitted with the stainless steel liner (107) welded on the side plate (101) to form a main dynamic sealing barrier, which effectively prevents seawater and mud from entering the bearing cavity and at the same time prevents the internal grease from leaking out. A static seal is achieved between the pulley shaft (203) and the shaft hole of the side plate (101) of the pulley frame (1) through the first O-ring (108); The sealing device (304) completely encloses the upper dynamic connection of the large nut (301) and the rotating shaft (302) to form an independent sealing cavity. The upper cover (3041) is statically sealed to the lower end plate (103) through the sealing gasket (3044), while the lower cover (3043) achieves dynamic sealing to the rotating shaft (302) through the second V-type oil seal (3045) and the second O-ring (3042). S4: When the grease needs to be replaced, the maintenance personnel do not need to disassemble any parts. They can simply add new grease into the sealed cavity through the oil inlet (6) on the lower end plate (103) or pulley shaft (203). Under pressure, the old grease will be squeezed out from the corresponding oil outlet (7). After the new grease overflows, the oil outlet (7) can be sealed with a plug (11) to complete the replacement. S5: At the boundary between the rotating shaft (302) and the lower cover (3043), there is a yellow paint marking line (8). As the pad (303) wears, the rotating shaft (302) moves relative to the lower end plate (103), causing the paint marking line (8) to move down. By observing the change in the position of the paint marking line (8), maintenance personnel can intuitively judge the wear degree of the pad (303), realize predictive maintenance, and avoid equipment failure due to excessive wear. S6: When performing major maintenance, the maintenance bracket (10) is installed through the reserved installation interface (9) at the four corners of the side plate (101). The other end of the maintenance bracket (10) is fixed on the auxiliary installation interface (501) of the external fixed frame (5), which rigidly fixes the entire pulley assembly, providing a stable and safe working platform for the operators and preventing the pulley assembly from accidentally rotating or tipping over during maintenance.

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