A variable support adjustment mechanism for a marine propulsion shafting and a control method

Abstract

The present application relates to the field of ship propulsion shafting support adjustment, and discloses a variable support adjustment mechanism and control method for a ship propulsion shafting, comprising a bearing seat, support wings being symmetrically arranged on the bottom of the two sides of the bearing seat; an installation base is arranged on the bottom of the bearing seat, and an adjustment assembly for adjusting the distance between the support wings and the installation base is arranged on the two sides of the bottom of the bearing seat; a pressure sensor is arranged on the bottom of the installation base; the pressure sensor transmits a pressure signal to a controller, and the controller controls the adjustment assemblies on the left and right sides of the bearing seat according to the pressure value. The control method is to actively adjust the bearing support height according to the real-time support force state during the operation of the ship, and a closed-loop adjustment process is formed through re-detection and re-calculation. The present application realizes high-precision adjustment of the support height of the ship propulsion shafting, actively optimizes the distribution of the load of the multi-support shafting, and realizes closed-loop control, thereby providing technical support for the local overload and load loss of the ship bearing.

Description

Technical Field

[0001] This invention relates to a shafting support adjustment mechanism and control method, and particularly to a variable support adjustment mechanism and control method for a ship propulsion shafting, belonging to the field of ship propulsion shafting support adjustment technology. Background Technology

[0002] Marine propulsion systems typically employ a multi-support shafting structure consisting of the main engine, couplings, thrust shaft, several intermediate shafts, and stern shaft. To ensure good power transmission performance and reliability during operation, each shaft section is usually supported by multiple bearings to maintain the proper spatial position of the shaft axis and control the bending moment and load distribution of the shafting.

[0003] In large ships, the propulsion shafting typically includes two stern shaft bearings and multiple intermediate shaft bearings, forming a typical multi-support structure. The installation height of the bearings directly affects the stress state and support reaction force distribution of the shafting, and is a crucial factor determining the alignment quality of the shafting. During the shipbuilding phase, the height of each bearing shim is usually adjusted through a static alignment process to ensure that the shafting achieves the expected load distribution under design conditions.

[0004] However, during actual operation, ships are subject to factors such as wave loads, changes in loading conditions, and temperature variations, leading to elastic deformation of the hull structure. Since shafting support points are typically rigidly connected to the hull structure, hull deformation causes changes in the relative positions of the bearings, resulting in a redistribution of shafting support reactions. Some bearings may experience increased load, abnormal oil film pressure, or localized overload, thereby affecting bearing life and the safety of the propulsion system.

[0005] In existing technologies, shaft alignment is mainly concentrated in the ship outfitting stage, where bearing height is adjusted once through calculation analysis or empirical methods. After installation, the bearing support structure is usually in a fixed state, making dynamic compensation difficult during ship operation. Although some technical solutions attempt to optimize alignment parameters during the installation stage using data analysis or intelligent algorithms, these methods are mostly applied to the initial installation or maintenance phases and fail to achieve real-time adjustment and active compensation during ship operation.

[0006] For example, Chinese patent CN121315633A discloses a method for aligning a ship's shafting with pre-installed flange bolts. The method involves supporting the shafting under alignment using temporary supports to ensure the flange's bending and offset meet design requirements; adjusting the main engine position to also meet these requirements; installing the connecting bolts and tightening the nuts to secure the flange connection; measuring the bearing load; comparing the measured load with the theoretical load value; and determining if alignment is unsuccessful if the measured load exceeds ±20% of the theoretical load value. The method then involves recalculating the shafting alignment to generate new theoretical load values ​​for the bearings. The method continues without removing the already installed flange bolts and nuts, and readjusting and measuring the shafting bearing load. This prior art primarily addresses remedial measures for unsuccessful shafting alignment during shipbuilding. After adjustment, the bearing support structure is typically fixed, making dynamic compensation difficult during ship operation.

[0007] Therefore, during ship operation, when the shafting is affected by the deformation of the hull and the support reaction force shifts, the traditional fixed support structure is difficult to dynamically adjust. The shafting is in a non-optimal stress state for a long time, resulting in energy efficiency loss. Summary of the Invention

[0008] Purpose of the invention: To address the shortcomings of existing technologies, this invention provides a variable support adjustment mechanism and control method for ship propulsion shafting, which can solve the problems of local overload, underload, and off-center load of bearings caused by the elastic deformation of the hull during ship operation.

[0009] Technical Solution: A variable support adjustment mechanism for a ship propulsion shaft includes a bearing housing, which rotatably supports a drive shaft and is fixed inside the hull. The bearing housing has a symmetrical "T"-shaped structure, with the central axis of the drive shaft extending horizontally along a plane of symmetry. Symmetrical support wing plates are provided on both sides of the bottom of the bearing housing. A mounting base is provided at the bottom of the bearing housing, and adjustment components for adjusting the distance between the support wing plates and the mounting base are provided on both sides of the mounting base. Pressure sensors are provided at the bottom of the mounting base, symmetrically arranged on both sides of the mounting base. The pressure sensors transmit pressure signals to a controller, which controls the adjustment components on both sides of the bearing housing according to the pressure value.

[0010] By setting up two symmetrically arranged and independently controlled adjustment components, the bearing housing can not only be raised and lowered as a whole, but also raised and lowered on one side to counteract the local overload, underload, and eccentric load problems of the bearing caused by the deformation of the hull during ship operation; thus improving the stability and precision of the bearing housing raising and lowering process.

[0011] In a preferred embodiment, to achieve height adjustment of the bearing housing by the adjustment assembly, the adjustment assembly includes a wedge and a lead screw. The wedge is movably mounted on the mounting base along its length. The lead screw cooperates with the wedge to drive the wedge to move back and forth along the length of the mounting base. The inclined surface of the wedge engages with the bottom of the support wing plate. When the wedge slides inward or outward from the mounting base, it raises or lowers the corresponding support wing plate. By horizontally moving the wedges of the adjustment assemblies on both sides, the raising and lowering of the support wing plates on both sides of the bottom of the bearing housing can be controlled separately. Synchronous raising and lowering on both sides can solve local overload or underload of the bearing, while asynchronous raising and lowering can solve local eccentric load problems of the bearing. The wedge and the mounting base, as well as the wedge and the support wing plate, can be connected by a heavy-duty guide rail and guide rail slider, or by a slider and slide groove (not shown), or other movable connection methods that can achieve smooth movement and withstand loads.

[0012] In a preferred embodiment, to prevent the device from undergoing unexpected displacement under ship vibration and operating condition fluctuations, a locking device is provided between the wedge and the support wing plate. When the locking device is locked, it locks the relative position of the wedge and the support wing plate. When unlocked, the wedge can slide relative to the support wing plate.

[0013] In a preferred embodiment, to ensure the stability and reliability of the support, the position between the support wing plate and the wedge needs to be locked after adjustment. The locking device includes a hollow shaft servo motor and a locking screw. The lower end of the locking screw is provided with an anti-rotation limiting structure. The wedge has an elongated hole that penetrates the wedge vertically, and the length of the elongated hole is set along the moving direction of the wedge.

[0014] The hollow shaft servo motor is fixedly mounted on the upper surface of the support wing plate and is connected to the controller via signal. The locking screw passes through the elongated hole of the wedge and the support wing plate from bottom to top and is driven by the hollow shaft servo motor. The anti-rotation limiting structure cooperates with the elongated hole to limit the rotation and lifting of the locking screw.

[0015] The locking screw is arranged vertically and connected to a hollow shaft servo motor. Driven by the servo motor, the locking screw moves vertically up and down. When the locking screw moves upward to its limit position, the anti-rotation limiting structure locks the vertical distance between the support wing plate and the wedge. When the locking screw moves downward, the anti-rotation limiting structure no longer restricts the vertical distance between the support wing plate and the wedge, allowing the wedge to move under the drive of the lead screw, thus unlocking the screw.

[0016] Preferably, to ensure that the locking screw can only move linearly in the vertical direction while locking the vertical distance between the support wing plate and the wedge, the anti-rotation limiting structure includes a limiting base plate and an anti-rotation limiting part. The limiting base plate is fixedly installed at the bottom end of the locking screw, and the width of the limiting base plate is greater than the width of the elongated hole. The anti-rotation limiting part is located inside the elongated hole and cooperates with the inner wall of the elongated hole to restrict the locking screw from rotating around its own central axis. Driven by a hollow shaft servo motor, the locking screw can only move linearly in the vertical direction.

[0017] When the locking screw moves upward, the upper surface of the limiting base plate comes into close contact with the lower surface of the wedge, thereby axially pressing and limiting the wedge's position, restricting its horizontal movement. When the locking screw moves downward, the upper surface of the limiting base plate separates from the lower surface of the wedge, thus releasing the wedge from locking. This structural design effectively prevents the wedge from undergoing unexpected horizontal displacement under ship vibration, impact, and operational fluctuations.

[0018] In a preferred embodiment, to prevent the rotation of the locking screw from affecting its linear movement in the vertical direction, the anti-rotation limiting part is a cylindrical structure fixedly installed on both sides of the locking screw. The center line of the cylindrical structure is in the same plane as the center line of the locking screw. The diameter of the cylindrical structure is smaller than the width of the elongated hole, and the height of the cylindrical structure is greater than the distance from the bottom surface of the wedge to the upper surface of the mounting base.

[0019] After the locking screw is installed, the cylindrical structure is inserted into the elongated hole. The outer diameter of the cylindrical structure matches the inner wall of the elongated hole to restrict the rotation of the locking screw. The height of the cylindrical structure is greater than the distance from the bottom surface of the wedge to the upper surface of the mounting base, which can prevent the cylindrical structure from falling off and improve the reliability of the anti-rotation function.

[0020] In a preferred embodiment, to improve the accuracy of shaft support reaction force detection, the pressure sensors are divided into two groups and symmetrically arranged on both sides of the center of the bearing housing; each group has at least four pressure sensors arranged along the bottom edge of the mounting base; all pressure sensors are connected to the controller signal.

[0021] The pressure sensor is used to detect the shaft support reaction force data at the bearing housing in real time. By setting 8 symmetrically distributed pressure sensors on the bottom end face of the bearing housing, the load change at the bearing housing can be detected in real time, providing data support for the controller to determine the current support status and calculate the target adjustment height.

[0022] A control method for a variable support adjustment mechanism of a ship's propulsion shaft system includes the following steps:

[0023] S1. Data acquisition: Real-time detection of shaft support reaction force data at bearing housing 1 using a pressure sensor, and transmission of the support reaction force data to the controller;

[0024] S2. The controller inputs the real-time support reaction force data into the pre-trained bearing load-height prediction model to calculate the current actual bearing height and the target optimal height.

[0025] S3. When the difference between the actual height and the target optimal height is greater than the preset threshold, the controller controls the locking device to separate the locking screw from the wedge, thus completing the unlocking.

[0026] S4. The controller calculates the required height adjustment of the bearing seat based on the current support reaction force data and the bearing load-height prediction model, controls the servo motor of the drive screw to rotate and drive the wedge to move horizontally, thereby raising and lowering the bearing seat to the target optimal height, and ensures that the bearing seat offset is less than the specified threshold during the adjustment process.

[0027] S5. After the height adjustment is completed, the controller controls the locking device to lock the locking screw and the wedge block in place.

[0028] S6. Collect support reaction force data again through the pressure sensor and input it into the prediction model for recalculation and verification. If the difference between the actual height and the target optimal height is still greater than the preset threshold, repeat steps S3 to S5.

[0029] Using the above method, the bearing support height can be actively adjusted according to the real-time support reaction force during ship operation, and a closed-loop adjustment process can be formed by re-detection and recalculation, thereby improving the adaptability of multi-support propulsion shaft systems to complex operating conditions.

[0030] In a preferred embodiment, to improve the accuracy of the target height calculation, the bearing load-height prediction model in step S2 is a prediction model based on an improved HHO-BP neural network. This model uses the bearing support reaction force as input and the vertical height of the bearing housing 1 as output for data fitting training. By using the bearing support reaction force as input and the vertical height of the bearing housing as output, a mapping relationship between the load state and the support height can be established, thereby quickly obtaining the corresponding target adjustment height after detecting the real-time support reaction force.

[0031] To construct the bearing load-height prediction model, the method for establishing the bearing load-height prediction model includes the following steps:

[0032] A1. Establish a three-dimensional equivalent model of the shafting system based on the ship propulsion shafting design drawings, and import the model into finite element simulation software;

[0033] A2. Set the stern shaft reference height and set the main shaft end as a fixed support constraint;

[0034] A3. Discretize the bearing height in increments of 0.2 mm or smaller, according to the allowable displacement range of each intermediate shaft bearing.

[0035] A4. Perform simulation calculations on each discretized working condition in sequence, record the bearing load data under each working condition, and generate a bearing load-height corresponding dataset.

[0036] A5. The improved Harris Eagle algorithm is used to globally optimize the hyperparameters of the BP neural network. The optimized BP neural network is trained using the bearing load-height correspondence dataset to obtain the bearing load-height prediction model.

[0037] To further improve prediction accuracy, the improved Harris Eagle algorithm includes a hybrid population initialization strategy and a periodic local search mechanism. These optimization methods enhance the prediction accuracy of the BP neural network and prevent premature convergence of the algorithm.

[0038] The improved Harris Eagle algorithm introduces a hybrid population initialization strategy and a periodic local search mechanism to enhance model prediction accuracy. The hybrid population initialization strategy strengthens the algorithm's global search capability, while the periodic local search mechanism improves its local optimization capability, thereby obtaining a better neural network hyperparameter configuration and improving the overall performance of the prediction model.

[0039] Beneficial effects: The present invention uses a servo motor to drive a lead screw to rotate and push a wedge to move horizontally. Then, through the cooperation between the wedge and the bearing seat, the horizontal displacement of the wedge is converted into the vertical displacement of the bearing seat, thereby achieving high-precision adjustment of the support height of the ship's propulsion shaft system. At the same time, through a pre-trained bearing load-height prediction model, the actual height of the current bearing is compared with the target optimal height in real time, thereby controlling the unlocking of the locking device, the adjustment of the adjustment component, and the re-locking after adjustment. This achieves active optimization distribution and closed-loop control of the load of multiple support shaft systems, providing technical support for solving the problems of local overload and underload of ship bearings. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the structure of the present invention connected to the drive shaft;

[0042] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0043] Figure 3 This is a schematic diagram of the structure of the adjustment component of the present invention;

[0044] Figure 4This is a partial view of the bearing housing and wedge block being installed together according to the present invention;

[0045] Figure 5 Partial view of the installation of the bearing housing with locking device and the wedge block according to the present invention. Figure 1 ;

[0046] Figure 6 Partial view of the installation of the bearing housing with locking device and the wedge block according to the present invention. Figure 2 ;

[0047] Figure 7 A distribution diagram of the pressure sensors at the bottom of the mounting base for this invention;

[0048] Figure 8 This is a front view of the pressure sensor at the bottom of the mounting base of the present invention.

[0049] Figure 9 This is the control flowchart of the present invention;

[0050] Figure 10 This is a structural diagram of the prediction model of the present invention. Detailed Implementation

[0051] 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.

[0052] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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 this invention.

[0053] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0054] like Figure 1 and 2 As shown, a variable support adjustment mechanism for a ship propulsion shaft includes a bearing housing 1, which supports a drive shaft and is rotatably fixed inside the hull. The bearing housing 1 has a symmetrical "T"-shaped structure, with the central axis of the drive shaft extending horizontally along a plane of symmetry. Support wing plates 11 are symmetrically arranged on both sides of the bottom of the bearing housing 1. A mounting base 2 is provided at the bottom of the bearing housing 1. Adjustment components 3 for adjusting the distance between the support wing plates 11 and the mounting base 2 are respectively provided between the support wing plates 11 on both sides of the bottom of the bearing housing 1. Pressure sensors 4 are provided at the bottom of the mounting base 2, and the pressure sensors 4 are symmetrically arranged on both sides of the mounting base 2. The pressure sensors 4 transmit pressure signals to a controller, and the controller controls the adjustment components 3 on the left and right sides of the bearing housing 1 according to the pressure value.

[0055] By setting two symmetrically arranged and independently controlled adjustment components 3, the bearing housing 1 can not only be raised and lowered as a whole, but also raised and lowered on one side to offset the local overload, underload and off-center load problems of the bearing caused by the deformation of the hull during the operation of the ship; thus improving the stability and accuracy of the bearing housing 1 during the raising and lowering process.

[0056] like Figure 3 and 4 As shown, to adjust the height of the bearing housing 1 using the adjustment component 3, the adjustment component 3 includes a wedge 31 and a lead screw 32. The wedge 31 is movably mounted on the mounting base 2 along its length. The lead screw 32 cooperates with the wedge 31 to drive the wedge 31 to move back and forth along the length of the mounting base 2. The inclined surface of the wedge 31 engages with the bottom of the support wing plate 11. When the wedge 31 slides inward or outward from the mounting base 2, it raises and lowers the support wing plate 11. By horizontally moving the wedges of the adjustment components 3 on both sides, the raising and lowering of the support wing plates 11 on both sides of the bottom of the bearing housing 1 can be controlled respectively. Synchronous raising and lowering on both sides can solve the problem of local overload or underload of the bearing, while asynchronous raising and lowering can solve the problem of local eccentric load of the bearing. The wedge 31 and the mounting base 2, as well as the wedge 31 and the support wing plate 11, can be connected by a heavy-duty guide rail and guide rail slider, or by a slider and slide groove (not shown), or other movable connection methods that can achieve smooth movement and bear load.

[0057] The wedge 31 has a wedge angle of 2° and is fixedly connected to the heavy-duty guide rail slider. The heavy-duty guide rail, which is adapted to the heavy-duty guide rail slider, is fixed on the mounting base 2. The lead screw 32 has a pitch of 2mm. During operation, the servo motor drives the lead screw 32 to rotate, and the lead screw 32 pushes the wedge 31 to move horizontally and linearly along the heavy-duty guide rail. The stroke of the wedge 31 is 250mm. Through the combination of the above mechanisms, the adjustment mechanism can meet the adjustment requirement of 0.02mm.

[0058] The upper part of the adjustment component 3 includes a heavy-duty guide rail and a heavy-duty guide rail slider, which cooperate with the bearing seat 1 to achieve shaft system adjustment. The heavy-duty guide rail slider is fixedly connected to the bearing seat 1, and the heavy-duty guide rail adapted to the heavy-duty guide rail slider is fixedly connected to the wedge block 31. The bearing seat is adjustable by 8.72mm.

[0059] like Figure 2 and 5 As shown, in order to prevent the device from undergoing unexpected displacement under ship vibration and operating condition fluctuations, a locking device 5 is provided between the wedge 31 and the support wing plate 11. When the locking device 5 is locked, it locks the relative position of the wedge 31 and the support wing plate 11. When unlocked, the wedge 31 can slide relative to the support wing plate 11.

[0060] like Figure 5 and 6 As shown, in order to achieve the stability and reliability of the support, it is necessary to lock the support wing plate 11 and the wedge block 31 at a certain position after the adjustment is completed. The locking device 5 includes a hollow shaft servo motor 51 and a locking screw 52. The lower end of the locking screw 52 is provided with an anti-rotation limiting structure 53. The wedge block 31 is provided with an elongated hole 311 that penetrates the wedge block 31 in the vertical direction. The length direction of the elongated hole 311 is set along the moving direction of the wedge block 31.

[0061] The hollow shaft servo motor 51 is fixedly installed on the upper surface of the support wing plate 11, and the hollow shaft servo motor 51 is connected to the controller signal; the locking screw 52 passes through the elongated hole 311 of the wedge 31 and the support wing plate 11 from bottom to top and is driven by the hollow shaft servo motor 51; the anti-rotation limiting structure 53 cooperates with the elongated hole 311 to limit the rotation and lifting of the locking screw 52.

[0062] The locking screw 52 is arranged vertically and is driven by the hollow shaft servo motor 51. The locking screw 52 moves up and down vertically under the drive of the hollow shaft servo motor 51. When the locking screw 52 moves upward to its limit position, the anti-rotation limiting structure 53 locks the vertical distance between the support wing plate 11 and the wedge block 31. When the locking screw 52 moves downward, the anti-rotation limiting structure 53 no longer restricts the vertical distance between the support wing plate 11 and the wedge block 31, and the wedge block 31 can move under the drive of the lead screw 32 to unlock.

[0063] To ensure that the locking screw 52 can only move linearly in the vertical direction while locking the vertical distance between the support wing plate 11 and the wedge block 31, the anti-rotation limiting structure 53 includes a limiting base plate 531 and an anti-rotation limiting part 532. The limiting base plate 531 is fixedly installed at the bottom end of the locking screw 52, ​​and the width of the limiting base plate 531 is greater than the width of the elongated hole 311. The anti-rotation limiting part 532 is located inside the elongated hole 311 and cooperates with the inner wall of the elongated hole 311 to restrict the locking screw 52 from rotating around its own central axis. Under the drive of the hollow shaft servo motor 51, the locking screw 52 can only move linearly in the vertical direction.

[0064] When the locking screw 52 moves upward, the upper surface of the limiting base plate 531 comes into close contact with the lower surface of the wedge 31, thereby axially pressing and limiting the position of the wedge 31, restricting its horizontal movement. When the locking screw 52 moves downward, the upper surface of the limiting base plate 531 separates from the lower surface of the wedge 31, thereby releasing the locking of the wedge 31. This structural design effectively prevents the wedge 31 from undergoing unexpected horizontal displacement under ship vibration, impact, and operational fluctuations.

[0065] To prevent the rotation of the locking screw 52 from affecting its linear movement in the vertical direction, the anti-rotation limiting part 532 is a cylindrical structure fixedly installed on both sides of the locking screw 52. The center line of the cylindrical structure is in the same plane as the center line of the locking screw 52. The diameter of the cylindrical structure is smaller than the width of the elongated hole 311, and the height of the cylindrical structure is greater than the distance from the bottom surface of the wedge 31 to the upper surface of the mounting base 2.

[0066] After the locking screw 52 is installed, the cylindrical structure is inserted into the elongated hole 311. The outer diameter of the cylindrical structure matches the inner wall of the elongated hole 311 to restrict the rotation of the locking screw 52. The height of the cylindrical structure is greater than the distance from the bottom surface of the wedge 31 to the upper surface of the mounting base 2, which can prevent the cylindrical structure from falling off and improve the reliability of the anti-rotation function.

[0067] The anti-rotation limiting part 532 can also be other non-cylindrical irregular structures at the bottom of the locking screw 52, ​​such as two parallel planes machined on a cylinder with a diameter greater than the width of the elongated hole 311, and the distance between the two parallel planes is less than the width of the elongated hole 311 (not shown in the figure).

[0068] like Figure 7 and 8 As shown, in order to improve the accuracy of shaft support reaction force detection, the pressure sensor 4 is divided into two groups and symmetrically arranged on both sides of the center of the bearing seat 1; the number of pressure sensors 4 in each group is at least four and is set along the bottom edge of the mounting base 2; all pressure sensors 4 are connected to the controller signal.

[0069] The pressure sensor 4 is used to detect the shaft support reaction force data at the bearing housing 1 in real time. By setting 8 symmetrically distributed pressure sensors 4 on the bottom end face of the bearing housing 1, the load change at the bearing housing 1 can be detected in real time, providing data support for the controller to judge the current support status and calculate the target adjustment height.

[0070] This symmetrical arrangement allows for multi-point acquisition of the support reaction force distribution of bearing housing 1 during adjustment and operation, thereby improving the comprehensiveness and accuracy of force detection. On the other hand, by comparing the detection data of pressure sensors 4 at corresponding positions on both sides of bearing housing 1, it is possible to promptly determine whether bearing housing 1 has a tendency to deviate from the center. Let the sum of the forces on the four sensors on the left be F1 and the sum of the forces on the four sensors on the right be F2, then L1 = F2·L / (F1+F2), L2 = F1·L / (F1+F2), and half of the difference between L1 and L2 is the distance of the shaft system from the center.

[0071] To achieve automatic control of the adjustment process, the controller is electrically connected to the pressure sensor 4, the hollow shaft servo motor 51, and the servo motor of the drive screw 32; the controller receives the support reaction force data collected by the pressure sensor 4, and sends action control commands to the servo motors of the hollow shaft servo motor 51 and the drive screw 32 according to the data.

[0072] By setting up a controller, the support reaction force data collected by the pressure sensor 4 can be transmitted to the controller in real time, and the controller can uniformly control the locking device 5 and the adjustment component 3 to achieve closed-loop control of unlocking, adjustment, locking and re-verification.

[0073] like Figures 1 to 9 As shown, a control method for a variable support adjustment mechanism of a ship's propulsion shaft system includes the following steps:

[0074] S1. The support reaction force data at the corresponding position of the bearing seat 1 is collected in real time by eight pressure sensors 4 set on the mounting base 2, and the support reaction force data is transmitted to the controller.

[0075] S2. The controller inputs the real-time support reaction force data into the pre-trained bearing load-height prediction model, calculates the current actual bearing height and the target optimal height, and compares the difference between the two; when the difference is greater than a preset threshold, it is determined that height adjustment is required.

[0076] S3. The controller sends an unlocking command to the locking device 5, and controls the hollow shaft servo motor 51 to drive the locking screw 52 to move downward in the vertical direction, so that the locking screw 52 separates from the wedge block 31, and the unlocking is completed.

[0077] S4. The controller calculates the target rotation angle required by the lead screw 32 based on the bearing height adjustment amount, and sends an adjustment command to the servo motor to control the lead screw 32 to rotate and push the wedge 31 to move in the horizontal direction. The wedge 31 cooperates with the bearing seat 1 to drive the bearing seat 1 to make vertical adjustment. During the adjustment process, the controller receives the support reaction force data fed back by the pressure sensor 4 in real time, calculates its distance from the center and corrects it in time to ensure that the force on both sides of the bearing seat 1 remains balanced.

[0078] S5. After the bearing seat 1 is adjusted to the target height, the controller sends a locking command to the locking device 5, controls the hollow shaft servo motor 51 to drive the locking screw 52 to move upward, so that the locking screw 52 and the wedge block 31 are locked again, thereby fixing the adjustment device 3.

[0079] S6. Transmit the adjusted support reaction force data to the controller again and input it into the bearing load-height prediction model for recalculation and verification. If the difference between the current actual bearing height and the target optimal height is still greater than the preset threshold, repeat steps S2 to S5 until the preset requirements are met.

[0080] like Figure 10 As shown, the bearing load-height prediction model is constructed using an improved HHO-BP neural network. This improved HHO-BP neural network is based on the standard backpropagation neural network, incorporating an improved Harris Eagle optimization algorithm to globally optimize the hyperparameters of the BP neural network, and combining a hybrid population initialization strategy and a periodic local search mechanism to improve the model's prediction accuracy and convergence stability.

[0081] The prediction model uses bearing load as input and bearing height as output for data fitting training. First, a three-dimensional equivalent model of the shafting system is established based on the ship's propulsion shafting design drawings, and this model is imported into finite element simulation software for simulation analysis. Then, the stern shaft reference height is set, and the main engine shaft end is set as a fixed support constraint. Next, according to the allowable displacement range of each intermediate shaft bearing, the bearing height is discretized at a step size of 0.2 mm. This step size ensures that the model's average absolute error is less than 0.03 mm, meeting adjustment requirements. Subsequently, simulation calculations are performed sequentially for each discretized operating condition, recording the bearing load data under each condition to generate a bearing load-height corresponding dataset. This dataset is then used to improve the training of the HHO-BP neural network.

[0082] The improved Harris Eagle algorithm suffers from reduced accuracy gains when the population size is greater than 25, while its global search capability is insufficient when the population size is less than 25. Considering both the accuracy of the prediction model and the training efficiency, the population size is set to 25. Since the axis support problem is not a purely random problem, the first 5 individuals are initialized based on preset values ​​from the experience of static axis alignment, making the initial solution close to the potential optimal solution region. The middle 5 individuals are generated through a globally uniform random sampling method to improve the global coverage of the solution space. The remaining 15 individuals are generated using a Gaussian distribution strategy, with the empirical value individuals as the mean and a small variance of 0.01-0.1 used for perturbation, so that the individuals are concentrated near the potential optimal solution region, thereby achieving a dynamic balance between global exploration and local focus.

[0083] The periodic local search mechanism comprehensively considers the sufficiency of global search and the timeliness of local fine-grained optimization. It is set to trigger a perturbation once every 10 generations. After the triggering condition is met, the Gaussian perturbation with an amplitude of 0.001-0.01 is applied to each hyperparameter dimension of the BP neural network based on the global optimal solution obtained in the current iteration, generating 5 candidate solutions. This amplitude can keep the candidate solutions within the neighborhood of the current global optimal solution and form sufficient differences within the neighborhood to improve the local optimization accuracy. Subsequently, the fitness of the candidate solutions and the current global optimal solution is evaluated. If there is a solution with better fitness among the candidate solutions, the current global optimal solution is updated with the better solution. This strategy can make the model achieve a better balance between global search and local search, further improve the optimization accuracy and avoid premature convergence of the algorithm.

[0084] The hyperparameter search range of the improved Harris Hawk algorithm for the BP neural network is shown in Table 1:

[0085] Table 1. Harris Hawk Algorithm Parameter Table

[0086]

[0087] The activation function is encoded as follows: 0 represents the ReLU function, 1 represents the Tanh function, and 2 represents the ELU function.

[0088] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0089] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A variable support adjustment mechanism for a ship propulsion shaft system, comprising a bearing housing (1), wherein the bearing housing (1) supports a drive shaft rotatably fixed inside the hull, characterized in that: The bearing seat (1) has a "丄"-shaped structure that is symmetrical left and right. The central axis of the transmission shaft extends horizontally along the symmetry plane, and support wing plates (11) are symmetrically provided at the bottoms on both sides of the bearing seat (1). An installation base (2) is provided at the bottom of the bearing seat (1), and an adjustment component (3) for adjusting the distance between the support wing plate (11) and the installation base (2) is respectively provided between the support wing plates (11) on both sides at the bottom of the bearing seat (1) and the installation base (2). A pressure sensor (4) is provided at the bottom of the installation base (2), and the pressure sensors (4) are symmetrically arranged on both sides of the installation base (2) left and right. The pressure sensor (4) transmits a pressure signal to the controller, and the controller controls the adjustment components (3) on the left and right sides of the bearing seat (1) respectively according to the pressure value.

2. The variable support adjustment mechanism for ship propulsion shafting according to claim 1, characterized in that: The adjustment component (3) includes a wedge block (31) and a screw rod (32). The wedge block (31) is movably installed on the installation base (2) along the length direction of the installation base (2), and the screw rod (32) cooperates with the wedge block (31) to drive the wedge block (31) to move back and forth along the length direction of the installation base (2). The inclined surface of the wedge block (31) cooperates with the bottom of the support wing plate (11). When the wedge block (31) slides inward and outward of the installation base (2), the lifting and lowering of the support wing plate (11) that cooperates with it are realized.

3. The variable support adjustment mechanism for ship propulsion shafting according to claim 2, characterized in that: A locking device (5) is provided between the wedge block (31) and the support wing plate (11). When the locking device (5) is locked, the relative positions of the wedge block (31) and the support wing plate (11) are locked, and when it is unlocked, the wedge block (31) can slide relatively.

4. The variable support adjustment mechanism for ship propulsion shafting according to claim 3, characterized in that: The locking device (5) includes a hollow shaft servo motor (51) and a locking screw rod (52). An anti-rotation limiting structure (53) is provided at the lower end of the locking screw rod (52). A long hole (311) that penetrates the wedge block (31) vertically is provided on the wedge block (31), and the length direction of the long hole (311) is arranged along the moving direction of the wedge block (31). The hollow shaft servo motor (51) is fixedly installed on the upper surface of the support wing plate (11), and the hollow shaft servo motor (51) is signal-connected to the controller; the locking screw rod (52) sequentially penetrates the long hole (311) of the wedge block (31) and the support wing plate (11) from bottom to top and is drivingly connected to the hollow shaft servo motor (51); the anti-rotation limiting structure (53) cooperates with the long hole (311) to limit the rotation and lifting amount of the locking screw rod (52).

5. The variable support adjustment mechanism for ship propulsion shafting according to claim 4, characterized in that: The anti-rotation limiting structure (53) includes a limiting bottom plate (531) and an anti-rotation limiting portion (532). The limiting bottom plate (531) is fixedly installed at the bottom end of the locking screw rod (52), and the width of the limiting bottom plate (531) is greater than the width of the long hole (311); the anti-rotation limiting portion (532) is located in the long hole (311) and cooperates with the inner wall of the long hole (311) to limit the rotation of the locking screw rod (52) around its own central axis.

6. The variable support adjustment mechanism for ship propulsion shafting according to claim 5, characterized in that: The anti-rotation limiting part (532) is a cylindrical structure fixedly installed on both sides of the locking screw (52). The center line of the cylindrical structure is in the same plane as the center line of the locking screw (52). The diameter of the cylindrical structure is smaller than the width of the elongated hole (311). The height of the cylindrical structure is greater than the distance from the bottom surface of the wedge (31) to the upper surface of the mounting base (2).

7. The variable support adjustment mechanism for ship propulsion shafting according to claim 1, characterized in that: The pressure sensors (4) are divided into two groups and are symmetrically arranged on both sides of the center of the bearing seat (1); each group of pressure sensors (4) has at least four sensors arranged along the bottom edge of the mounting base (2); all pressure sensors (4) are connected to the controller signal.

8. The variable support adjustment mechanism for ship propulsion shafting according to claim 4, characterized in that: The controller is electrically connected to the pressure sensor (4), the hollow shaft servo motor (51), and the servo motor of the drive screw (32); the controller receives the support reaction force data collected by the pressure sensor (4) and sends action control commands to the servo motors of the hollow shaft servo motor (51) and the drive screw (32) according to the data.

9. A control method for a variable support adjustment mechanism for a ship propulsion shafting system according to claim 8, characterized in that, Includes the following steps: S1. Data acquisition: Real-time detection of shaft support reaction force data at bearing housing 1 via pressure sensor (4), and transmission of the support reaction force data to controller; S2. The controller inputs the real-time support reaction force data into the pre-trained bearing load-height prediction model to calculate the current actual bearing height and the target optimal height. S3. When the difference between the actual height and the target optimal height is greater than the preset threshold, the controller controls the locking device (5) to act, so that the locking screw (52) separates from the wedge (31) and completes the unlocking. S4. The controller calculates the required height adjustment of the bearing seat (1) based on the current support reaction force data and the bearing load-height prediction model, controls the servo motor of the drive screw (32) to rotate and drive the wedge (31) to move horizontally, thereby driving the bearing seat (1) to rise and fall to the target optimal height, and ensuring that the offset of the bearing seat (1) is less than the specified threshold during the adjustment process. S5. After the height adjustment is completed, the controller controls the locking device (5) to operate, so that the locking screw (52) and the wedge (31) are locked in place; S6. Collect the support reaction force data again through the pressure sensor (4) and input it into the prediction model for recalculation and verification. If the difference between the actual height and the target optimal height is still greater than the preset threshold, repeat steps S3 to S5.

10. The variable support adjustment mechanism for ship propulsion shafting according to claim 9, characterized in that: The bearing load-height prediction model in step S2 is a prediction model based on an improved HHO-BP neural network. This model uses the bearing support reaction force as input and the vertical height of the bearing housing (1) as output for data fitting training. The method for establishing the bearing load-height prediction model includes the following steps: A1. Establish a three-dimensional equivalent model of the shafting system based on the ship propulsion shafting design drawings, and import the model into finite element simulation software; A2. Set the stern shaft reference height and set the main shaft end as a fixed support constraint; A3. Discretize the bearing height with an appropriate step size according to the allowable displacement range of each intermediate shaft bearing. A4. Perform simulation calculations on each discretized working condition in sequence, record the bearing load data under each working condition, and generate a bearing load-height corresponding dataset. A5. The improved Harris Eagle algorithm is used to globally optimize the hyperparameters of the BP neural network. The optimized BP neural network is trained using the bearing load-height correspondence dataset to obtain the bearing load-height prediction model. The improved Harris Eagle algorithm includes a hybrid population initialization strategy and a periodic local search mechanism. These optimization methods enhance the prediction accuracy of the BP neural network and prevent premature convergence.

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