Non-uniform-speed wave generation equipment based on bidirectional cam groove and arc-shaped plate

Abstract

The invention discloses non-uniform-speed wave making equipment based on a bidirectional cam groove and an arc-shaped plate, and belongs to the technical field of wave simulation. The equipment comprises a wave-making water tank and a wave-making device, wherein the wave-making device comprises an arc-shaped wave-making plate and a driving system; the driving system adopts a two-way groove-shaped cam-double crank sliding block composite mechanism, through a double-cam groove with a specific asymmetric outline, constant-speed rotation of a motor is directly converted into non-constant-speed rectangular linear reciprocating motion of a wave making plate, and the dynamic rhythm of'fast-rising and slow-falling 'of natural waves is accurately simulated. Meanwhile, the arc-shaped wave making plate effectively reduces water resistance and energy loss. The problems that a traditional push plate wave maker is single in motion characteristic, distorted in waveform and low in efficiency are solved, dynamic and vivid test waves with high wave surface quality can be generated, and the simulation degree and reliability of a physical model test are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of wave simulation technology, and more specifically, to a highly realistic wave-generating device for scenarios such as marine engineering experiments, port and waterway research, and aquatic ecosystem simulation, particularly a mechanical wave-generating device capable of accurately simulating the non-uniform motion characteristics of natural waves. Background Technology

[0002] In the fields of marine engineering, hydraulic technology, and related experimental research, physical model testing is an important means of studying the interaction between waves and structures. As the core equipment for generating experimental waves, the performance of the wave generator directly determines the accuracy and reliability of the experiment. Currently, common wave generators are mainly classified into push-plate type, piston type, pneumatic type, and hydraulic type according to their driving method. Among them, the mechanically driven push-plate wave generator is widely used due to its relatively simple structure and direct control.

[0003] Existing mechanical pusher wave generators mostly employ classic crank-connecting rod mechanisms or rack and pinion mechanisms for motion conversion. While the crank-connecting rod mechanism is simple in structure, the pusher's trajectory is an approximate sine curve rather than an ideal straight line when converting rotary motion into linear motion. Furthermore, it suffers from instability and significant impact near the dead center, resulting in waves with steep leading edges and dragging trailing edges, leading to severe waveform distortion. Although the rack and pinion mechanism can achieve precise linear transmission, it requires extremely high manufacturing and installation precision. Under prolonged humid, high-load reciprocating motion conditions, the tooth surfaces are prone to wear, pitting, and even tooth breakage, resulting in high maintenance costs. Additionally, it is prone to vibration and noise during high-frequency operation.

[0004] More importantly, whether it's a crank-connecting rod or a rack and pinion, the motion of the wave-generating plate driven by them is usually a uniform or near-uniform linear reciprocating motion. However, real waves in nature exhibit significant non-uniform characteristics in the movement of water particles and the undulation of the wave surface. That is, the rising phase of the wave (wave formation) is often faster, while the falling phase (wave receding) is relatively slower. This dynamic rhythm cannot be reproduced by uniform motion. Therefore, the waves generated by existing equipment have a fundamental deficiency in dynamic similarity and cannot meet the increasingly demanding requirements of modern experiments for refined wave simulation.

[0005] Furthermore, traditional wave-generating plates are mostly planar plate structures. During the water propulsion process, planar plates have a large contact surface with the water and act directly, which easily generates significant wave-making resistance and wave-breaking phenomena, resulting in low energy transfer efficiency and the formation of strong eddies behind the plate, interfering with the flow field. This leads to broken wave surfaces, rapid energy attenuation, and difficulty in forming smooth and stable propulsion waves, especially in simulating the contours of deep-water waves.

[0006] In summary, existing wave-generating devices have significant shortcomings in terms of the smoothness and accuracy of motion conversion, the dynamic realism of wave generation, and energy transfer efficiency. Developing a wave-generating device capable of achieving precise linear drive at non-uniform speeds and better interaction with water bodies has become an urgent need to improve the simulation accuracy of wave physics model experiments. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a non-uniform wave-generating device based on a bidirectional cam groove and an arc-shaped plate. This device, through an innovative composite transmission mechanism, directly converts uniform rotation into precisely plannable non-uniform linear motion. Combined with an optimized arc-shaped wave-generating plate, it can efficiently and stably generate non-uniform waves that highly simulate the dynamic characteristics of nature.

[0008] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: A non-uniform wave-generating device based on a bidirectional cam groove and an arc plate mainly includes a wave-generating water tank, a wave-generating device, and an optional circulating water system.

[0009] The wave-generating device is the core improvement, comprising a drive system and a wave-generating plate. The drive system innovatively employs a bidirectional grooved cam-double crank-slider composite mechanism. The core of this mechanism lies in a cam disk with a specially contoured bidirectional cam groove. When the motor drives the cam disk to rotate at a constant speed, the constraint and drive of the corresponding crank rollers by the different contoured cam grooves on both sides, combined with a precise guiding mechanism and a linkage crank, decomposes and synthesizes the rotational motion into a linear motion in a two-dimensional plane. Through the precise design of the cam groove contour, the speed ratio of this linear motion (i.e., the relationship between displacement and cam angle) can be varied as needed, thus naturally outputting a non-uniform reciprocating linear motion with a specific acceleration law. This motion, integrated through a cross-slider connecting rod, directly drives the wave-generating plate to perform a non-uniform linear reciprocating motion along a set rectangular trajectory, exhibiting "fast start, slow fall" or other customized rhythms.

[0010] The wave-generating plate abandons the traditional planar design and adopts an arc-shaped plate structure. The curvature of this arc-shaped plate has been optimized through fluid dynamics, with an optimal arc angle of 7-8 degrees. When pushing water, the arc-shaped plate surface can guide the water flow more smoothly, reduce frontal impact and eddy current generation, reduce wave-making resistance, and more effectively convert energy into wave potential and kinetic energy, thereby forming waves with a smoother surface and a contour closer to a natural sine curve.

[0011] Preferably, the drive system includes two independent sets of bidirectional slotted cam-double crank slider composite mechanisms symmetrically arranged, which drive the left and right sides of the back of the wave-generating plate respectively via connecting arms. This dual-side synchronous drive method ensures that the wide-width wave-generating plate is subjected to uniform force, moves smoothly, and is free from torsional deformation, further guaranteeing the consistency of the generated waves.

[0012] As a further preferred embodiment, the device also includes a circulating water system, consisting of a motor impeller assembly and a flow divider. The flow divider separates parallel upper and lower channels within the wave-generating tank, with the wave-generating plate located in the upper channel. The motor impeller assembly drives water circulation, simulating a water flow environment, allowing the generated waves to propagate and evolve in a context closer to real-world flow.

[0013] Compared with the prior art, the present invention has the following significant advantages: 1. Revolutionary breakthrough in motion characteristics: It is the first to combine cam groove transmission with crank-slider mechanism to directly generate non-uniform linear motion that can be precisely programmed. This fundamentally solves the problem that traditional mechanisms can only generate waves at a uniform speed, making the generated waves highly similar to natural waves in dynamic rhythm.

[0014] 2. Smooth and Precise Transmission: The cam mechanism provides smooth, shock-free transmission, and its contour design ensures accurate motion transmission without theoretical errors. The guiding mechanism and linear motion unit guarantee the precision of the motion trajectory of the actuator (wave generator), avoiding the trajectory deviation problems of traditional crank-connecting rods.

[0015] 3. Significantly improved wave quality: The combination of the arc-shaped wave plate and non-uniform speed drive not only reduces energy consumption, but more importantly, it can produce high-quality waves with complete wave surfaces, beautiful contours, and realistic dynamics, greatly improving the simulation accuracy of the experiment.

[0016] 4. Reliable structure and wide adaptability: The core transmission components are subjected to reasonable stress, resulting in low wear and long service life. By replacing cam discs with different profiles or wave-generating plates with different curvatures, the motion law and waveform of the waves can be flexibly changed to meet the needs of different test conditions, demonstrating strong versatility.

[0017] 5. Easy maintenance: Modular design, key components such as cam disc and wave generator are easy to disassemble and replace, resulting in low maintenance costs. Attached Figure Description

[0018] Figure 1 This is an isometric schematic diagram of the overall structure of a non-uniform wave generation device. Figure 2 This is a top view schematic diagram of the overall structure of a non-uniform wave generation device. Figure 3 yes Figure 2 Schematic diagram of the cross section at point AA; Figure 4 yes Figure 1 A schematic diagram of the bidirectional slotted cam-double crank slider compound mechanism in direction a (with hidden mounting bracket). Figure 5 for Figure 1A schematic diagram of the bidirectional slotted cam-double crank slider compound mechanism in the b direction (with hidden mounting bracket).

[0019] In the diagram: 1-Wave-generating water tank; 2-Flow divider; 21-Upper flow channel; 22-Lower flow channel; 3-Motor impeller assembly; 4-Wave-generating plate; 51-Mounting bracket; 52-Bidirectional slotted cam mechanism; 521-Camshaft; 522-First cam groove; 523-Second cam groove; 524-Cam disc; 53-First articulated segmented crank; 531-First roller; 532-First pin; 533-First segment; 534-Second segment; 535-First articulated shaft; A1-First guide mechanism; 54-Second articulated segmented crank; 541-Second roller; 542-Second pin; 543-Third section; 544-Fourth section; 545-Second articulated shaft; A2-Second guide mechanism; 55 - Cross-shaped sliding link; 551 - First sliding groove (longitudinal); 552 - Second sliding groove (transverse); 56-Dual-axis linear motion unit; 561-Basic axis guide rail slider pair (lateral); 562-Superimposed axis guide rail slider pair (longitudinal); 563-Connecting plate; 57-Connecting arm assembly; 571-Connecting arm; 572-Buffer joint. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the following description is intended to explain the invention, not to limit it.

[0021] like Figures 1 to 5 As shown, the non-uniform wave-generating device of this embodiment mainly includes a cuboid wave-generating tank 1. As... Figure 3 As shown, the water tank 1 is divided into two channels, an upper channel 21 and a lower channel 22, by a horizontal flow divider 2. Multiple motor impeller assemblies 3 are installed in the lower channel, driving water to flow from the lower channel 22 to the upper channel 21, forming a circulating water flow to simulate a constant background flow. The core of the wave-generating device—an arc-shaped wave-generating plate 4—is installed at the beginning of the upper channel 21, and its drive system is located inside the water tank 1 or on an upper support.

[0022] like Figure 4 and Figure 5As shown, the core of the drive system is a bidirectional grooved cam-double crank-slider composite mechanism arranged symmetrically on both sides. Taking one side as an example, this mechanism is mounted on a robust steel structure mounting bracket 51. A servo motor (not shown in the attached drawings) drives the camshaft 521 to rotate via a coupling. A bidirectional grooved cam mechanism 52 is fixed on the camshaft 521, the main body of which is a cam disk 524. The two end faces of the disk are respectively machined with a closed first cam groove 522 and a second cam groove 523. According to the non-uniform characteristics of the required wave (such as requiring the wave-generating plate to be pushed out quickly and retracted slowly), the contours of the two grooves are designed as asymmetrical curves. For example, the "push stroke" segment of the first cam groove 522 has a large lift change rate (corresponding to fast acceleration), while the "return stroke" segment changes gradually; the second cam groove 523 is designed to match the movement of the other degree of freedom.

[0023] The first kinematic chain includes a first articulated segmented crank 53. Its first segment 533 is connected to the mounting bracket 51 via a first guide mechanism A1 (such as a set of linear guides) and is constrained to slide only in a direction perpendicular to the movement direction of the wave-making plate 4 (referred to as longitudinal). A first roller 531 at the end of the first segment 533 is embedded in a first cam groove 522. When the cam disc 524 rotates, the contour of the first cam groove 522 forces the first roller 531, along with the first segment 533, to perform a longitudinal reciprocating linear motion, the speed of which is determined by the contour. The second segment 534 of the first articulated segmented crank 53 is hinged to the mounting bracket 51 via a first hinge shaft 535. A first pin 532 is mounted on the free end of the second segment 534. The longitudinal linear motion of the first segment 533 forces the second segment 534 to oscillate longitudinally around the first hinge shaft 535.

[0024] The second kinematic chain includes a second articulated segmented crank 54. Its third segment 543 is connected to the mounting bracket 51 via a second guide mechanism A2 (another set of linear guides) and is constrained to slide only in a direction parallel to the wave-generating direction (referred to as lateral). A second roller 541 at its end is embedded in a second cam groove 523. The rotation of the cam disk 524 drives the third segment 543 to perform a lateral reciprocating linear motion. The fourth segment 544 of the second articulated segmented crank 54 is hinged to the mounting bracket 51 via a second hinge shaft 545, with its free end's second pin 542 serving as the output. The lateral linear motion of the third segment 543 forces the fourth segment 544 to oscillate laterally around the second hinge shaft 545.

[0025] The motion synthesis component is the cross-slide link 55. It is connected to the mounting bracket 51 via a dual-axis linear motion unit 56. Specifically, the base axis guide rail slider pair 561 (lateral guide) is fixed to the mounting bracket 51, and a connecting plate 563 is mounted on its slider. The superimposed axis guide rail slider pair 562 (longitudinal guide) is fixed to the connecting plate 563, and the cross-slide link 55 is fixed to the slider of this pair. This structure allows the cross-slide link 55 to move only within the lateral-longitudinal plane defined by 561 and 562, and the movement in the two directions does not interfere with each other. The cross-slide link 55 has a first groove 551 (longitudinal) and a second groove 552 (lateral) that are perpendicular to each other.

[0026] The linkage is as follows: the first pin 532 is inserted into the first slide groove 551, and the second pin 542 is inserted into the second slide groove 552. When the second segment 534 swings, it pushes the cross slide groove connecting rod 55 to move laterally via the first pin 532; when the fourth segment 544 swings, it pushes the cross slide groove connecting rod 55 to move longitudinally via the second pin 542. The vector combination of these two movements is the actual motion trajectory of the center of the cross slide groove connecting rod 55. Due to the special contour design of the cam grooves 522 and 523, this combined motion is a closed rectangular trajectory, and its speed is non-uniform when moving along this trajectory.

[0027] The end of the cross-shaped sliding rod 55 is connected to the back of the arc-shaped wave-making plate 4 via a connecting arm assembly 57. The connecting arm assembly 57 may include a rigid connecting arm 571 and a buffer joint 572 with a certain buffering or self-aligning function (such as an elastic bushing or spherical bearing) to compensate for minor installation errors and reduce impact. The two-sided mechanism drives a wave-making plate 4 together through the same connection method to ensure its translation.

[0028] like Figure 4 As shown, the wave-generating plate 4 is an inwardly concave arc-shaped plate in the wave-generating direction, and its arc angle α is preferably designed to be 7.5 degrees. This arc can effectively reduce the impact pressure at the moment of pushing water, allowing the water to rise and leave the plate surface more smoothly, forming an ideal wave surface.

[0029] Work process: The servo motor is started, driving the cam disk 524 to rotate at a constant speed. Cam grooves 522 and 523, through their respective kinematic chains, drive the cross-slide connecting rod 55 to perform a preset non-uniform rectangular trajectory motion. This motion is transmitted to the arc-shaped wave-generating plate 4 via the connecting arm 57, causing it to perform the same non-uniform linear reciprocating motion in the upper channel 21. The wave-generating plate 4 propels the water with a rhythm of "rapid forward thrust and slow backward retreat," and, in conjunction with its arc-shaped surface, generates a non-uniform propulsion wave in the upper channel with realistic dynamic characteristics and a smooth wave surface. By adjusting the speed of the servo motor, the frequency of the wave can be changed linearly; by replacing the cam disk 524 with cam grooves of different profiles, the "non-uniform" rhythm and amplitude of the wave can be changed; by replacing the wave-generating plate 4 with one of different curvatures, the cross-sectional shape of the generated wave can be adjusted.

[0030] The above embodiments are merely preferred examples of the present invention and are not intended to limit the present invention. Any simple modifications, equivalent substitutions, and improvements made based on the essential spirit of the present invention, such as changing the specific contour curve of the cam groove, adopting other forms of linear guide mechanisms, or adjusting the layout of the circulating water system, should be included within the protection scope of the present invention.

Claims

1. A non-uniform wave-generating device based on a bidirectional cam groove and an arc-shaped plate, comprising a wave-generating water tank, characterized in that, Also includes: A wave-generating device, the wave-generating device comprising a drive system and a wave-generating plate; The drive system includes a bidirectional slotted cam-double crank slider composite mechanism, which converts the rotational motion of the motor into the non-uniform rectangular linear reciprocating motion of the wave-making plate. The wave-generating plate is an arc-shaped plate.

2. The device according to claim 1, characterized in that, The bidirectional slotted cam-double crank slider composite mechanism includes: Mounting rack; A bidirectional slotted cam mechanism rotatably mounted on the mounting bracket has a rotation axis and a first cam slot and a second cam slot located on both sides of the rotation axis with different profiles; The first kinematic chain includes a first articulated segmented crank and a first guide mechanism; the first segment of the first articulated segmented crank forms a first linear sliding pair perpendicular to the wave-generating direction with the mounting frame through the first guide mechanism, and the end of the first segment is provided with a first roller that cooperates with the first cam groove; the second segment of the first articulated segmented crank is hinged to the mounting frame, and its free end is provided with a first drive pin. The second kinematic chain includes a second articulated segmented crank and a second guide mechanism; the third segment of the second articulated segmented crank forms a second linear sliding pair parallel to the wave-generating direction with the mounting frame through the second guide mechanism, and the end of the third segment is provided with a second roller that cooperates with the second cam groove; the fourth segment of the second articulated segmented crank is hinged to the mounting frame, and its free end is provided with a second drive pin. A cross-shaped sliding rod is provided with a first sliding groove and a second sliding groove that are perpendicular to each other. The first drive pin is slidably disposed in the first sliding groove, and the second drive pin is slidably disposed in the second sliding groove. A dual-axis linear motion unit is mounted on a mounting frame and connected to the cross-shaped sliding rod, which is used to constrain the cross-shaped sliding rod to move only in a two-dimensional plane parallel to and perpendicular to the wave-generating direction; The cross-shaped sliding groove connecting rod is connected to the wave-generating plate via a transmission connection.

3. The device according to claim 2, characterized in that, Two independent bidirectional grooved cam-double crank slider composite mechanisms are symmetrically arranged on both sides of the back of the wave-generating plate. The cross-slide connecting rods of the two composite mechanisms are rigidly connected to the wave-generating plate through their respective connecting arm assemblies.

4. The device according to claim 2, characterized in that, The contours of the first cam groove and the second cam groove are designed according to the non-uniform motion law of the target, so that when the bidirectional groove cam mechanism rotates at a constant speed, it drives the wave-making plate to produce a dynamic reciprocating motion of "accelerating up and down, decelerating down".

5. The device according to any one of claims 1-4, characterized in that, The arc angle of the arc plate is 7-8 degrees, and its radius of curvature is designed to adapt to the contour of the target wave.

6. The device according to any one of claims 2-4, characterized in that, The first and second guiding mechanisms are linear guide rail pairs or guide rod slider pairs.

7. The device according to any one of claims 2-4, characterized in that, The dual-axis linear motion unit includes a base axis guide rail slider pair and a superimposed axis guide rail slider pair. The guiding direction of the base axis guide rail slider pair is parallel to the wave-generating direction, and the guiding direction of the superimposed axis guide rail slider pair is perpendicular to the wave-generating direction. The cross-groove connecting rod is fixed to the slider of the superimposed axis guide rail slider pair.

8. The device according to claim 2, characterized in that, The connection between the connecting arm assembly and the wave-generating plate is provided with an elastic buffer or a ball joint.

9. The device according to claim 1, characterized in that, It also includes a circulating water system, which includes a motor impeller assembly and a flow divider plate disposed in the wave-making water tank. The flow divider plate divides the interior of the water tank into parallel upper and lower channels, and the wave-making plate is disposed in the upper channel.

10. The device according to claim 1 or 9, characterized in that, The motor in the drive system is a servo motor.

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