Direct drive marine winch system with constant air gap and multi-stage cooling

Abstract

The application belongs to the technical field of marine equipment and specifically relates to a direct-drive marine winch system with constant air gap and multi-stage cooling. The system comprises a rack, a control unit, a drum motor arranged on the rack, a cooling device arranged on the drum motor, a brake device and a cable arranging mechanism arranged between the rack and the drum motor, and the control unit is electrically connected with the drum motor, the cable arranging mechanism and the brake device to realize the winding and unwinding of the cable and the heave compensation. The drum motor directly drives the winding and unwinding of the cable, and the structure is simple and does not need intermediate mechanical transmission mechanisms such as reducers. This not only greatly reduces mechanical loss, but also has the advantages of high transmission efficiency, small space occupation and small inertia, so that the winch has faster response speed when performing wave heave compensation.

Description

Technical Field

[0001] This invention belongs to the field of marine equipment technology, specifically relating to a direct-drive marine winch system with constant air gap and multi-stage cooling. Background Technology

[0002] Marine winches are crucial equipment for hoisting marine equipment, conducting scientific research, and resource development. In actual operations, to ensure the stability and safety of the hoisted equipment, marine winches need to compensate for the heave and sag effects of wind and waves on research vessels. This requires the winch to continuously, precisely, and rapidly reverse direction to adjust the cable length. Currently, some marine winches mainly use multiple drum drive motors in conjunction with planetary reducers to drive the drum rotation and cable winding and unwinding, and rely on a hydraulic system to brake the drum. This approach, due to the inclusion of reducers, results in a long mechanical transmission path from the drive motor to the drum, leading to a large overall system inertia. This inadequate response speed and energy efficiency makes it difficult to meet the demands of high-frequency, rapid wave compensation. Furthermore, the complex hydraulic braking system has low reliability in complex marine environments far from land and with limited maintenance materials. Furthermore, in deep-sea operations, the multi-layered, heavy-duty cables exert enormous compressive stress on the outer wall of the drum, causing radial deformation of the drum. In traditional integrated motor and drum structures, this deformation is directly transmitted to the motor stator and rotor, causing changes in the electromagnetic air gap and resulting in severe torque pulsation, which greatly affects the stability and winding accuracy of the winch. Summary of the Invention

[0003] To address the problems of high mechanical losses, low transmission efficiency, and slow heave compensation response in existing marine winches due to their reliance on intermediate mechanical transmission mechanisms such as reducers, this invention provides a direct-drive marine winch system with constant air gap and multi-stage cooling.

[0004] This invention is achieved through the following technical solution: A direct-drive marine winch system with constant air gap and multi-stage cooling includes a frame, a control unit, a drum motor mounted on the frame, a cooling device mounted on the drum motor, and a braking device and a cable laying mechanism located between the frame and the drum motor. The control unit is electrically connected to the drum motor, the cable laying mechanism, and the braking device to realize the winding and unwinding of the cable and heave compensation.

[0005] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling includes a control unit comprising an acceleration sensor for acquiring the wave rise velocity. During heave compensation, the control unit controls the system based on the data acquired by the acceleration sensor: when the ship is rising due to waves, the control unit controls the drum motor to rotate forward to release the cable at a speed equal to the sum of the hoisting equipment's release speed and the wave rise velocity; when the ship reaches a high point, the control unit controls the braking device to decelerate and brake the drum motor; subsequently, when the ship is falling due to waves, the control unit controls the drum motor to rotate in reverse to retract the cable.

[0006] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling is provided. The drum motor is an external rotor direct-drive motor, which includes a fixed shaft, a fixed shaft sleeve and a stator core located outside the fixed shaft, a drum end cover rotatably connected to the fixed shaft via bearings, a drum outer wall detachably connected to the drum end cover, a permanent magnet sleeve located inside the drum outer wall and having a gap between it and the drum outer wall, and a permanent magnet located on the permanent magnet sleeve and having an electromagnetic air gap between it and the stator core.

[0007] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling is provided with a reinforcing ring on the inner side of the middle of the outer wall of the drum. One end of the permanent magnet sleeve is sealed and connected to the reinforcing ring, and the other end is connected to the drum end cap.

[0008] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling includes multiple stator cores, the windings of each stator core being evenly staggered by a preset electrical angle along the circumference to reduce torque pulsation.

[0009] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling includes a braking device comprising a brake seat fixed to the frame, a plurality of electromagnetic brakes disposed on the brake seat, a brake gear set connected to the electromagnetic brakes, and a brake disc disposed on the drum motor and meshing with the brake gear set.

[0010] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling includes a first cooling mechanism for cooling the cable and a second cooling mechanism for cooling the interior of the drum motor.

[0011] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling includes a first cooling mechanism comprising a cable cooling port on the fixed shaft, a cable connecting groove arranged circumferentially along the drum end cap and communicating with the cable cooling port, a cable cooling channel arranged radially along the drum end cap, and a plurality of cable cooling holes provided on the outer wall of the drum and communicating with the gap between the outer wall of the drum and the permanent magnet sleeve. One end of the cable cooling channel communicates with the cable connecting groove, and the other end communicates with the gap between the outer wall of the drum and the permanent magnet sleeve.

[0012] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling includes a second cooling mechanism comprising a threaded groove between the fixed shaft and the fixed shaft sleeve, a first motor cooling port on the fixed shaft and connecting the electromagnetic air gap between the permanent magnet sleeve and the stator core, and a second motor cooling port connecting the threaded groove, wherein the threaded groove connects the electromagnetic air gap between the permanent magnet sleeve and the stator core.

[0013] As described above, a direct-drive marine winch system with constant air gap and multi-stage cooling includes a control unit that further comprises a rotation speed sensor disposed on the cable laying mechanism for acquiring the cable winding and unwinding speed.

[0014] Compared with the prior art, the present invention has the following advantages: 1. This invention uses an external rotor drum motor to directly drive the cable winding and unwinding, which is simple in structure and does not require intermediate mechanical transmission mechanisms such as a reducer. This not only greatly reduces mechanical losses, but also has the advantages of high transmission efficiency, small space occupation, and small inertia, enabling the winch to have a faster response speed when performing wave heave compensation.

[0015] 2. This invention features a permanent magnet sleeve with a certain gap between it and the outer wall of the drum. When the outer wall of the drum deforms under the pressure of a heavy-duty cable, this deformation is isolated by the gap and will not affect the change in the electromagnetic air gap of the drum motor, thus ensuring that the torque pulsation of the drum motor is small and the operation is more stable.

[0016] 3. The cooling device of the present invention has a heat dissipation passage inside the drum motor to cool down the internal heat-generating components; at the same time, in conjunction with the first cooling mechanism, the cooling medium can be sprayed outward through small holes on the outer wall of the drum to directly cool the external cable, which greatly improves the heat dissipation performance of the overall system under high-load continuous operation.

[0017] 4. This invention is driven directly by electricity, without hydraulic transmission, and is equipped with an electromagnetic braking device. It can automatically brake in the event of a power failure, effectively ensuring the safety of launching marine equipment, and has the advantages of simple structure, simple control, fast response, and easy maintenance.

[0018] 5. The drum motor of the present invention has redundant multiple stators, which are staggered at a certain angle. Combined with the reinforcing ring on the inner side of the outer wall of the drum, the structural rigidity and reliability of the drum motor are further improved, and the torque pulsation of the direct drive motor is effectively reduced. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional perspective view of an embodiment of the present invention; Figure 2 yes Figure 1 Top view; Figure 3 yes Figure 2 Cross-sectional view at point AA; Figure 4 This is a three-dimensional perspective view of the roll end cap in an embodiment of the present invention; Figure 5 yes Figure 4 Side view; Figure 6 yes Figure 5 Cross-sectional view at point BB; Figure 7 This is a three-dimensional perspective view of the fixed axis in an embodiment of the present invention. Detailed Implementation

[0021] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] Please see Figures 1 to 7 A direct-drive marine winch system with constant air gap and multi-stage cooling includes a frame 1, a control unit 2, a drum motor 3 mounted on the frame 1, a cooling device 4 mounted on the drum motor 3, a braking device 5 and a cable laying mechanism 6 located between the frame 1 and the drum motor 3. The control unit 2 is electrically connected to the drum motor 3, the cable laying mechanism 6 and the braking device 5 to realize the winding and unwinding of the cable and heave compensation.

[0023] In this embodiment, when the system is operating normally, the control unit 2 monitors the ship's heave status in real time by acquiring data from external sensors. During wave heave compensation, when the ship is rising due to waves, the control unit 2 coordinates with the drum motor 3 to rotate forward to release the cable. At this time, the release speed is precisely set to the sum of the hoisting equipment's release speed and the wave's rising speed. When the ship rises to its highest point with the waves, the control unit 2 issues a command to cause the braking device 5, located between the frame 1 and the drum motor 3, to rapidly decelerate and brake the drum motor 3. Subsequently, when the ship is falling due to waves, the control unit 2 again controls the drum motor 3 to reverse and retract the cable. At the same time, the cable laying mechanism 6, in coordination with the rotation of the drum motor 3, guides the cable to be neatly arranged layer by layer. The cooling device 4 continuously supplies cooling medium to the core heat-generating components inside the drum motor 3 and the external cable throughout the entire operation of the equipment to remove heat. The beneficial effect of the above electromechanical-hydraulic coupling structure is that the system completely eliminates the intermediate mechanical transmission mechanism such as the reducer required by traditional marine winches. The drum motor 3 directly drives the cable winding and unwinding, fundamentally eliminating mechanical transmission losses. It has significant advantages such as high transmission efficiency, small space occupation, small system inertia, fast dynamic response, and high overall reliability. Its all-electric control architecture, together with the braking device 5, can achieve automatic safety braking in the event of a power failure. It is not only safe and reliable and has a simplified structure, but also has simple control logic and is easy to maintain in the later stage, which greatly improves the operation accuracy and the safety of marine equipment hoisting and launching under harsh sea conditions.

[0024] Furthermore, as a preferred embodiment of this solution and not a limitation, the control unit 2 includes an acceleration sensor 21 for acquiring the wave rise speed. When performing heave compensation, the control unit 2 controls the ship based on the data acquired by the acceleration sensor 21: when the ship is rising due to waves, the control unit 2 controls the drum motor 3 to rotate forward to release the cable, with the release speed being the sum of the hoisting equipment's release speed and the wave rise speed; when the ship rises to a high point, the control unit 5 decelerates and brakes the drum motor 3; subsequently, when the ship is falling due to waves, the control unit 2 reverses the drum motor 3 to retract the cable.

[0025] In this embodiment, the control unit 2 collects the vertical acceleration signal of the ship under the action of waves in real time through its included acceleration sensor 21, and converts it into the instantaneous rise or fall speed of the waves through internal microprocessor integration calculation. When the system switches to heave compensation mode, the control unit 2 calculates the wave motion data and preset operation instructions in real time. During the stage when the ship is lifted up by the waves, the control unit 2 sends a forward rotation command to the drum motor 3 to accelerate the release of the cable, and the release speed is precisely matched to the vector sum of the original set release speed of the hoisting equipment and the real-time rise speed of the waves, so as to offset the upward pull of the ship on the underwater equipment in real time. When the ship reaches the peak of the wave and the vertical velocity approaches zero, the control unit 2 quickly commands the braking device 5 to intervene and precisely decelerate and brake the drum motor 3 to offset the inertia of the drum and prevent the cable from slipping. If the cable becomes excessively slack or tangled, and then begins to sink with the waves after the vessel passes the wave crest, control unit 2 immediately switches commands to control drum motor 3 to reverse, quickly retrieving the cable at a compensation rate matching the vessel's descent speed. This avoids sudden tension on the cable caused by the vessel sinking. The significant benefit of this control logic, based on real-time attitude monitoring and transient speed dynamic compensation, is that it can minimize the physical interference of wave heave motion on underwater equipment under severe sea conditions. It not only effectively avoids the severe impact loads, alternating stresses, and breakage risks caused by sudden slack and tension of the cable, but also significantly extends the service life of the cable and winch transmission system. Furthermore, it ensures that the operating depth of high-precision marine scientific instruments or heavy exploration and mining equipment remains absolutely stable underwater, achieving safe and stable deployment and retrieval of marine equipment, and thus significantly expanding the safe operating window for research vessels in higher sea state conditions.

[0026] Furthermore, as a preferred embodiment of this solution and not a limitation, the drum motor 3 is an external rotor direct drive motor, which includes a fixed shaft 31, a fixed shaft sleeve 32 and a stator core 33 disposed outside the fixed shaft 31, a drum end cover 35 rotatably connected to the fixed shaft 31 via a bearing 34, a drum outer wall 36 detachably connected to the drum end cover 35, a permanent magnet sleeve 37 disposed inside the drum outer wall 36 and having a gap between it and the drum outer wall 36, and a permanent magnet 38 disposed on the permanent magnet sleeve 37 and having an electromagnetic air gap between it and the stator core 33.

[0027] In this embodiment, the drum motor 3 is an external rotor direct drive motor. Its fixed shaft 31 serves as a stationary reference component, stably supporting the internal stator core 33 via a fixed shaft sleeve 32. When an alternating current is applied to the windings of the stator core 33, a rotating magnetic field is generated between it and the permanent magnet 38 mounted on the permanent magnet sleeve 37 across an electromagnetic gap. This generates a driving torque through electromagnetic induction, directly driving the permanent magnet sleeve 37 and its associated drum outer wall 36 to rotate against the external load. Since the drum outer wall 36 is rotatably supported on the fixed shaft 31 via drum end caps 35 and bearings 34 at both ends, it can... The electromagnetic driving force of the motor is directly converted into the mechanical rotational motion of the outer wall 36 of the drum for winding and unwinding the cable. In deep-sea heavy-load operations, the tightly wound multiple layers of cable will generate significant radial compressive stress on the outer wall 36 of the drum, causing unavoidable minor deformation. This invention provides a physical deformation isolation gap between the outer wall 36 of the drum bearing the compressive stress and the permanent magnet sleeve 37 on which the permanent magnet 38 is installed. This gap completely absorbs and physically isolates the deformation when the outer wall 36 of the drum is strongly compressed and deformed inward by the cable, preventing rigid transmission to the internal permanent magnet sleeve 37 and thus avoiding... The significant advantage is that it breaks through the technical bottleneck of traditional integrated winch drum deformation under pressure directly causing uneven air gap in the motor. It ensures that deformation of the drum's outer arm under cable compression does not affect the electromagnetic air gap change of the drum motor, thus ensuring minimal torque pulsation of the direct-drive motor under heavy load conditions and guaranteeing high efficiency and smooth motor operation. Furthermore, this structure, which eliminates the need for a reducer and directly drives the cable winding and unwinding via the external rotor drum motor, offers advantages such as high transmission efficiency, small footprint, low inertia, fast response, and high reliability. The fixing method between the stator core 33 and the fixed bushing 32 is not limited to conventional methods. The heat-fitting or keyed connection can also be replaced by a hydraulic expansion sleeve connection with a high-pressure oil hole to facilitate the disassembly and maintenance of large marine winches on the work site. The drum outer wall 36, which is detachably connected to the drum end cover 35, can be implemented by a high-strength flange bolt group connection, end face toothed disc meshing connection, or countersunk screw fastening structure with high-precision positioning pins to facilitate the core pulling and maintenance of the internal permanent magnet and stator assembly. At the same time, the permanent magnet sleeve 37 can not only be made of conventional high-strength non-magnetic stainless steel to prevent magnetic leakage, but can also be made of carbon fiber composite material that takes into account both high strength and lightweight.

[0028] Furthermore, as a preferred embodiment of this solution and not a limitation, a reinforcing ring 361 is provided on the inner side of the middle part of the outer wall 36 of the drum, and one end of the permanent magnet sleeve 37 is sealed and connected to the reinforcing ring 361, and the other end is connected to the drum end cover 35.

[0029] In this embodiment, facing the enormous radial compressive stress generated by the tightly wound layers of heavy-duty cables often spanning thousands of meters in deep-sea operations, the middle section of the long-span, thin-walled drum is prone to inward deflection and collapse deformation. This invention addresses this by adding a protruding reinforcing ring 361 to the inner side of the middle section of the drum's outer wall 36, which is equivalent to adding a strong annular support rib inside the thin-walled cylinder. This significantly increases the cross-sectional moment of inertia of the drum's outer wall against radial deformation. Simultaneously, one end of the permanent magnet holder 37, which carries a high-precision magnet, is securely supported and sealed to a rigid... The extremely high reinforcing ring 361 connects at one end to the already thick and strong drum end cap 35, allowing the permanent magnet sleeve 37 to be securely bridged between the high-rigidity nodes at both ends. The significant benefits of this are twofold: firstly, the reinforcing ring 361 fundamentally improves the overall structural rigidity and load-bearing capacity of the drum motor, effectively resisting catastrophic mechanical deformation caused by the superposition of tension from multiple layers of cables; secondly, this ingenious support method, combined with the pre-reserved gap between the outer wall and the sleeve, completely prevents external damage to the drum. The slight deformation of the wall 36 under pressure is physically transmitted to the internal core electromagnetic components, ensuring that the electromagnetic air gap between the motor rotor and stator remains absolutely constant under any extreme heavy load or impact conditions. This gives the motor excellent operating characteristics of high reliability and low torque pulsation. In addition, this sealed connection structure can effectively isolate the inner and outer chambers and accurately guide the flow of the subsequent cooling medium to prevent it from leaking into the air gap and generating additional fluid resistance. Furthermore, in addition to using conventional high-temperature and oil-corrosion resistant fluororubber O-rings or X-rings for the sealing connection between the permanent magnet sleeve 37 and the reinforcing ring 361, it can also be replaced with a stepped labyrinth seal, an end face mechanical seal with wave spring compensation, or, under the premise of no need for maintenance and disassembly, a permanent physical dense weld using continuous laser deep penetration welding. This allows for extremely flexible adaptation to the customized and highly reliable structural design requirements of direct-drive marine winches of different tonnages, from small-scale scientific research sampling in shallow waters to the retrieval and unloading of heavy exploration and mining equipment of tens of thousands of tons in the deep sea.

[0030] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, it includes a plurality of stator cores 33, wherein the windings of each stator core 33 are arranged circumferentially staggered by a preset electrical angle to reduce torque pulsation.

[0031] In this embodiment, during the operation of the direct-drive motor, the electromagnetic torque generated by a single stator winding inevitably contains spatial harmonic components, thus causing periodic fluctuations in the output torque. This invention addresses this by configuring multiple redundant stator cores 33 inside the motor and intentionally offsetting their windings by a preset electrical angle in the spatial circumferential direction. This causes a corresponding phase shift in the torque harmonic phase generated by each stator when operating independently. When these multiple alternating electromagnetic torques simultaneously act on the same external rotor assembly and are spatially superimposed, the peaks and troughs of the torque pulsations generated by each stator can be mutually neutralized and canceled out, thereby reducing the... The significant benefits are that, not only does it substantially reduce the overall torque ripple of the drum motor from the underlying electromagnetic design logic, giving the drum motor a characteristic of low torque ripple, it allows the outer rotor drum to achieve extremely smooth and stable low-speed, high-torque output during precision marine equipment hoisting and wave heave compensation, greatly reducing the interference of mechanical vibration and noise on the data of deep-sea high-precision detection instruments, but this redundant multi-stator architecture also gives the entire power system an extremely high fault tolerance rate and high reliability. Even in complex marine operating environments far from the mainland, with harsh maintenance conditions and limited spare parts, even if a winding of one of the stator cores 33 malfunctions... In the event of a sudden short circuit or drive module burnout, the control unit can quickly isolate the faulty phase through a redundant fault-tolerant control algorithm and instruct the remaining healthy stator cores to continue operating to maintain the basic operation of the winch. This ensures that the marine winch can still safely complete the recovery of underwater equipment and prevent significant property damage. The specific value of this "preset electrical angle" can be flexibly set according to the number of stator sets. For example, when using two sets of three-phase windings, the electrical angle can be staggered by 30 degrees; when using three sets of three-phase windings, the electrical angle can be staggered by 20 degrees. Furthermore, the physical arrangement of multiple stator cores 33 can be implemented not only as multiple independent sections connected in series along the fixed shaft, but also as... The stator slots are arranged in parallel on the same circumferential surface, divided into sector segments. For the power supply and drive method of this multi-stator winding structure, multiple independent three-phase frequency converters can be used to independently power each stator to achieve complete decoupling and isolation in the physical hardware architecture. Alternatively, a highly integrated multi-phase (such as six-phase, nine-phase, or fifteen-phase) customized inverter can be used in conjunction with the space vector pulse width modulation (SVPWM) algorithm for centralized and coordinated drive. This allows for customized implementation schemes for deep-sea direct-drive motors that balance extreme stability and extremely high survivability, based on the bus power capacity of different research vessels and the installation space limitations of the winch nacelle.

[0032] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the braking device 5 includes a brake seat 51 fixed on the frame 1, a plurality of electromagnetic brakes 52 disposed on the brake seat 51, a brake gear set 53 connected to the electromagnetic brakes 52, and a brake disc 54 disposed on the drum motor 3 and meshing with the brake gear set 53.

[0033] In this embodiment, during normal heave compensation or routine cable winding and unwinding operations of the marine winch, multiple electromagnetic brakes 52 mounted on the high-rigidity brake seat 51 of the frame 1 are in an energized and released state. At this time, the brake disc 54 fixed on the drum motor 3 rotates synchronously with the outer rotor of the motor, driving the brake gear set 53 meshing with it to be in a free-running state without resistance, without causing braking interference to the drum motor 3. However, when the control unit issues deceleration or hovering commands, or when the ship encounters a sudden power failure such as a complete power outage, the electromagnetic brakes 52 instantly lose power and lock up (i.e., power failure braking safety logic), generating a strong frictional braking torque. This braking torque is transmitted and amplified through the brake gear set 53 and then acts on the large-diameter brake disc 54, thereby forcing the drum motor 3 to overcome its huge inertia and stop rotating quickly and smoothly. Furthermore, multiple electromagnetic brakes 52 can withstand long-term heavy-load hovering or frequent... Under deceleration and wave compensation conditions, alternating start-stop operation can be achieved through the control unit. The significant benefits of this are twofold: First, it cleverly utilizes the mechanical amplification effect of gear transmission to achieve reliable braking of heavy-duty, high-inertia drums with a small-volume and low-power electromagnetic brake, completely replacing the traditional hydraulic braking system and eliminating the hidden dangers of pipeline leakage, response lag, and cumbersome maintenance. Second, the redundant parallel arrangement of multiple braking modules gives the entire lifting system an extremely high safety limit. Even if some braking units experience mechanical failure or electrical burnout, the remaining healthy brakes can still work together to provide sufficient parking torque, ensuring that expensive underwater scientific research equipment does not slip or fall. At the same time, the alternating working mechanism effectively avoids the high-temperature thermal fade and excessive wear of friction pads caused by continuous friction of a single brake, greatly improving the durability of the braking system and the response stability under harsh sea conditions.

[0034] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the cooling device 4 includes a first cooling mechanism 41 for cooling the cable and a second cooling mechanism 42 for cooling the interior of the drum motor 3.

[0035] In this embodiment, facing the enormous thermal load generated by the marine winch under high-frequency wave heave compensation conditions, the cooling device 4 simultaneously delivers cooling medium to two core heat-generating areas through a fluid circuit. The second cooling mechanism 42 specifically guides the cooling medium deep into the internal core area of ​​the drum motor 3, flowing through the stator heat source and the electromagnetic air gap. Through fluid heat exchange, it rapidly removes the massive heat generated during electromagnetic conversion, thereby maintaining an extremely low operating temperature rise inside the motor. Simultaneously, the first cooling mechanism 41 is responsible for diverting the cooling medium to the external structure of the drum motor 3, directly acting on the multi-layered, tightly wound cable that rapidly heats up due to extremely high dynamic tension and frequent bending friction. The invention absorbs and dissipates the accumulated heat energy of the cable through contact heat exchange and other methods. The significant benefit of this invention is that it innovatively solves the bottleneck of extreme heat concentration and heat dissipation difficulties caused by the high integration of integrated direct-drive winches. The dual-pronged internal and external synchronous composite heat dissipation mechanism not only completely eliminates the fatal hidden dangers of permanent magnet demagnetization due to high temperature and thermal aging of stator insulation layer inside the motor, but also greatly improves the continuous heavy-load output capacity and working life of the drum motor. It also effectively prevents the risk of strength reduction and breakage of polymer synthetic cable or wire rope due to heat generated by motor overheating, and comprehensively ensures the continuity and extremely high safety of deep-sea equipment hoisting operations.

[0036] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the first cooling mechanism 41 includes a cable cooling port 411 disposed on the fixed shaft 31, a cable connecting groove 412 disposed circumferentially along the drum end cover 35 and communicating with the cable cooling port 411, a cable cooling channel 413 disposed radially along the drum end cover 35, and a plurality of cable cooling holes 414 disposed on the outer wall 36 of the drum and communicating with the gap between the outer wall 36 of the drum and the permanent magnet sleeve 37. One end of the cable cooling channel 413 communicates with the cable connecting groove 412, and the other end communicates with the gap between the outer wall 36 of the drum and the permanent magnet sleeve 37.

[0037] In this embodiment, when the winch is running and performing the external cable cooling task, the pressurized cooling medium is first pumped in from the cable cooling port 411 on the stationary fixed shaft 31, and then seamlessly flows into the cable connecting groove 412 arranged circumferentially on the inner side of the rotatable drum end cover 35. The cable connecting groove 412 cleverly acts as a dynamic distribution ring for the exchange of dynamic and static fluids, so that no matter what rotation angle or speed the drum motor is at, the cooling medium can be continuously introduced into the cable cooling channel 413 extending radially along the drum end cover 35, and flows radially outward under the dual action of centrifugal force and external pump pressure, and then smoothly injected into the annular gap reserved between the drum outer wall 36 and the permanent magnet sleeve 37. This isolation gap is perfectly reused as a uniform and stable axial flow guide cavity. Finally, the cooling medium is sprayed outward through multiple cable cooling holes 414 densely distributed on the drum outer wall 36, directly and comprehensively penetrating and wetting the outer surface. This invention utilizes a compact internal slotted structure to perfectly solve the problems of dynamic and static sealing and high-pressure conduction in the continuous delivery of cooling fluid by a drum rotating at high speed from a stationary axis. This not only eliminates the need for traditional, bulky, and corroded mechanical rotary joints, making the winch more streamlined and compact and significantly reducing the failure rate of pipeline leaks, but also creatively utilizes the pressure deformation isolation gap inside the drum, giving it both excellent mechanical stress isolation and fluid pressure stabilization and flow equalization. This ensures that the cooling medium can be evenly distributed from all angles of the drum's outer wall at a constant pressure, completely eliminating overheating, hardening, thermal fatigue, or accelerated aging of the cable due to localized heat dissipation dead zones. This drastically improves the high-frequency continuous winding and unwinding life and ultimate breaking strength retention rate of heavy-duty deep-sea cables under harsh sea conditions.

[0038] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the second cooling mechanism 42 includes a threaded groove 421 disposed between the fixed shaft 31 and the fixed shaft sleeve 32, a first motor cooling port 422 disposed on the fixed shaft 31 and communicating with the electromagnetic air gap between the permanent magnet sleeve 37 and the stator core 33, and a second motor cooling port 423 communicating with the threaded groove 421. The threaded groove 421 communicates with the electromagnetic air gap between the permanent magnet sleeve 37 and the stator core 33.

[0039] In this embodiment, when the marine winch performs high-intensity lifting and lowering operations, causing a rapid increase in the internal temperature of the motor, the insulating cooling medium, driven by an external circulation pump, can be forcibly pumped in from the second motor cooling port 423 located on the fixed shaft 31. The cooling medium first enters the long-stroke threaded groove 421 machined on the mating surface between the fixed shaft 31 and the fixed shaft sleeve 32, and flows in a combined circumferential and axial spiral along the spiral trajectory, fully absorbing and carrying away the heat accumulated on the inner ring of the stator core 33 and the base of the fixed shaft 31. Subsequently, the cooling medium, having absorbed some heat, smoothly overflows from the end of the threaded groove 421 and seamlessly merges into the narrow electromagnetic air gap between the permanent magnet sleeve 37 and the stator core 33, forming a high-speed axial or spiral scouring liquid flow in the air gap. This flow directly engages in zero-distance deep convection heat exchange with the stator winding ends, stator tooth surface, and rotating permanent magnet surface, which are at their highest temperature. Finally, the cooling medium, carrying a large amount of heat energy, passes through the second motor cooling port 423 located on the fixed shaft 31. The first motor cooling port 422 at one end flows out of the motor body and back to the external radiator for cooling circulation (the flow direction of the cooling medium can also flow in the opposite direction from the first motor cooling port 422 to the second motor cooling port 423 according to the actual heat field distribution). The significant beneficial effect of this is that the present invention creatively integrates the physical assembly gap of the direct drive motor with the heat dissipation channel to the extreme. On the one hand, the threaded groove 421 greatly extends the residence time and effective heat exchange area of ​​the cooling medium in the core heat-generating area inside the motor, and induces strong enhanced heat transfer turbulence inside the fluid, which significantly improves the heat exchange efficiency of the bottom layer. On the other hand, by allowing the insulating medium to flow directly through the electromagnetic air gap, the "targeted" precise cooling of the stator copper loss heat source and the rotor eddy current heat source is achieved, eliminating the local heat island effect that is easy to occur inside the sealed drum motor under the heavy load of deep sea, and fundamentally eliminating the fatal risks of irreversible high-temperature demagnetization of permanent magnets and thermal breakdown of stator insulation layer.

[0040] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the control unit 2 also includes a rotation speed sensor 22 disposed on the cable laying mechanism 6 and used to obtain the cable winding and unwinding speed.

[0041] In this embodiment, when the marine winch performs high-precision retrieval and wave heave compensation, the cable will inevitably continuously pass through and closely adhere to the guide wheel or cable pulley of the cable laying mechanism 6. Since the working diameter of the guide wheel is fixed, the speed sensor 22, directly mounted on the rotating shaft of the guide wheel or the follow-up speed measuring wheel, can continuously collect the rotation pulse signal of the wheel in real time. After receiving the signal, the control unit 2, combined with the known fixed circumference of the guide wheel, can directly calculate the actual linear retrieval speed of the cable at this time through the microprocessor. The significant benefit of this is that the present invention completely overcomes the problem of traditional winches relying solely on measuring the speed of the main drive motor to indirectly estimate the cable speed. The huge cumulative speed measurement error caused by the constantly changing number of cable winding layers on the drum (leading to changes in the effective winding diameter) is addressed by directly obtaining the most accurate linear motion speed of the cable at the end of the cable laying mechanism. This provides the control unit 2 with the most accurate and reliable closed-loop feedback data source for accurately calculating and matching the sum of the launching speed of the hoisting equipment and the rising speed of the waves when performing complex wave heave compensation. This not only significantly improves the dynamic tracking accuracy of wave compensation and the sensitivity of system response, but also effectively prevents the cable from becoming instantly loose and knotted or breaking due to compensation lag or overshoot under severe sea conditions. This ensures the absolute safety and stability of the launching and lowering process of expensive deep-sea scientific research instruments and large-tonnage detection equipment.

[0042] The working principle of this embodiment is as follows: In marine equipment hoisting and wave heave compensation operations, the control unit coordinates the cable laying mechanism and the gearless external rotor drum motor to directly drive the cable for efficient deployment and retrieval. When encountering wave heave, the control unit dynamically adjusts the forward and reverse rotation of the drum motor and the activation and deactivation of the braking device based on the real-time wave rise speed and cable deployment / retrieval speed to precisely offset the impact of the ship's vertical displacement on the hoisting equipment. Under this heavy-load condition, the radial mechanical deformation caused by the strong compression of the multi-layered cable against the drum's outer wall is effectively isolated by the physical gap reserved between the drum's outer wall and the internal permanent magnet sleeve, ensuring the absolute constancy of the motor's electromagnetic air gap and stable low-torque pulsation output. At the same time, the cooling device continues to operate. The cooling medium flows through the motor to deeply liquid cool the core heat-generating components and smoothly passes through the aforementioned isolation gap and is sprayed outward through the through-holes in the drum's outer wall, synchronously convectively cooling the externally high-frequency friction cable. Thus, with a fully electrically controlled direct-drive architecture, the hoisting and deployment of deep-sea equipment can be completed safely, stably, and with high precision under complex sea conditions.

[0043] The above are embodiments provided in conjunction with specific content, and it is not intended that the specific implementation of the present invention be limited to these descriptions. Any method or structure that is similar to that of the present invention, or any technical deductions or substitutions made under the premise of the present invention, should be considered within the scope of protection of the present invention.

Claims

1. A direct-drive marine winch system with constant air gap and multi-stage cooling, characterized in that, It includes a frame (1), a control unit (2), a drum motor (3) mounted on the frame (1), a cooling device (4) mounted on the drum motor (3), a braking device (5) and a cable laying mechanism (6) located between the frame (1) and the drum motor (3). The control unit (2) is electrically connected to the drum motor (3), the cable laying mechanism (6) and the braking device (5) to realize the winding and unwinding of the cable and the compensation for heave and sag.

2. The direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 1, characterized in that, The control unit (2) includes an acceleration sensor (21) for acquiring the wave rise speed. When performing heave compensation, the control unit (2) controls the ship based on the data acquired by the acceleration sensor (21): when the ship is rising due to the waves, the control unit (2) controls the drum motor (3) to rotate forward to release the cable. The release speed is the sum of the hoisting equipment's release speed and the wave rise speed. When the ship rises to a high point, the control unit (5) decelerates and brakes the drum motor (3). Subsequently, when the ship is falling due to the waves, the control unit (2) controls the drum motor (3) to rotate in reverse to retract the cable.

3. A direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 1, characterized in that, The drum motor (3) is an external rotor direct drive motor, which includes a fixed shaft (31), a fixed shaft sleeve (32) and a stator core (33) located outside the fixed shaft (31), a drum end cover (35) rotatably connected to the fixed shaft (31) via a bearing (34), a drum outer wall (36) detachably connected to the drum end cover (35), a permanent magnet sleeve (37) located inside the drum outer wall (36) and having a gap between it and the drum outer wall (36), and a permanent magnet (38) located on the permanent magnet sleeve (37) and having an electromagnetic air gap between it and the stator core (33).

4. A direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 3, characterized in that, A reinforcing ring (361) is provided on the inner side of the middle part of the outer wall (36) of the drum. One end of the permanent magnet sleeve (37) is sealed and connected to the reinforcing ring (361), and the other end is connected to the drum end cap (35).

5. A direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 3, characterized in that, It includes multiple stator cores (33), and the windings of each stator core (33) are evenly staggered by a preset electrical angle along the circumference to reduce torque pulsation.

6. A direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 1, characterized in that, The braking device (5) includes a brake seat (51) fixed on the frame (1), a plurality of electromagnetic brakes (52) provided on the brake seat (51), a brake gear set (53) connected to the electromagnetic brakes (52), and a brake disc (54) provided on the drum motor (3) and meshing with the brake gear set (53).

7. A direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 3, characterized in that, The cooling device (4) includes a first cooling mechanism (41) for cooling the cable and a second cooling mechanism (42) for cooling the inside of the drum motor (3).

8. A direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 7, characterized in that, The first cooling mechanism (41) includes a cable cooling port (411) disposed on the fixed shaft (31), a cable connecting groove (412) disposed circumferentially along the drum end cap (35) and communicating with the cable cooling port (411), a cable cooling channel (413) disposed radially along the drum end cap (35), and a plurality of cable cooling holes (414) disposed on the outer wall (36) of the drum and communicating with the gap between the outer wall (36) of the drum and the permanent magnet sleeve (37). One end of the cable cooling channel (413) communicates with the cable connecting groove (412), and the other end communicates with the gap between the outer wall (36) of the drum and the permanent magnet sleeve (37).

9. A direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 7, characterized in that, The second cooling mechanism (42) includes a threaded groove (421) between the fixed shaft (31) and the fixed shaft sleeve (32), a first motor cooling port (422) on the fixed shaft (31) and connected to the electromagnetic air gap between the permanent magnet sleeve (37) and the stator core (33), and a second motor cooling port (423) connected to the threaded groove (421). The threaded groove (421) connects to the electromagnetic air gap between the permanent magnet sleeve (37) and the stator core (33).

10. A direct-drive marine winch system with constant air gap and multi-stage cooling as described in claim 1, characterized in that, The control unit (2) also includes a rotation speed sensor (22) disposed on the cable laying mechanism (6) and used to obtain the cable winding and unwinding speed.

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