Horizontal hydraulic diaphragm pump

Abstract

The application discloses a horizontal hydraulic diaphragm pump and belongs to the technical field of diaphragm pumps. The horizontal hydraulic diaphragm pump comprises a power end, a hydraulic end, an auxiliary system and a control system. The hydraulic end comprises a hydraulic chamber adopting an asymmetric gradually changing cross section design, a gravity compensation type gradient rigidity composite diaphragm, a diaphragm chamber and an integrated intelligent exhaust device, the top of the hydraulic chamber is provided with a spherical crown gas collection concave cavity; the diaphragm is divided into a central flexible area, a transition buffer area and an edge rigid area along the radial direction, and a reinforcing framework is embedded in the lower semicircular area; the intelligent exhaust device comprises a bubble aggregation cavity, a gas-liquid separation microchannel group, a liquid level sensor and an exhaust electromagnetic valve. The auxiliary system comprises a double-cavity pre-pressing pulsation buffer, an air bag is arranged in a main buffer cavity, and a spring piston is arranged in an auxiliary buffer cavity. The control system adopts a pressure gradient self-adaptive reversing control and an iterative learning control algorithm to inhibit pressure pulsation, and solves the problems of asymmetric force bearing of the diaphragm, gas accumulation in the hydraulic chamber, large flow pulsation and reversing impact and the like under the horizontal arrangement.

Description

Technical Field

[0001] This invention relates to the field of diaphragm pump technology, and specifically to a horizontal hydraulic diaphragm pump. Background Technology

[0002] A hydraulic diaphragm pump is a positive displacement reciprocating pump that uses hydraulic oil as the transmission medium and isolates the hydraulic chamber from the medium chamber through a diaphragm. It is widely used in mining, metallurgy, and chemical industries to transport high-concentration, highly abrasive slurries or corrosive media. Compared to reciprocating piston pumps, the medium chamber of a diaphragm pump is completely isolated from the power end, preventing wear and corrosion of precision moving parts by the transported medium, making it particularly suitable for transporting media under harsh conditions. Depending on the pump body arrangement, diaphragm pumps can be divided into vertical and horizontal structures. The horizontal arrangement has advantages such as convenient installation and maintenance, low foundation height, stable center of gravity, and ease of multi-cylinder arrangement, and has been widely adopted in practical engineering applications.

[0003] The horizontal arrangement of hydraulic diaphragm pumps presents several unique technical challenges. In horizontal operation, the hydraulic oil within the hydraulic chamber experiences uneven pressure distribution on the diaphragm surface due to gravity. The lower part of the diaphragm experiences higher static pressure than the upper part, leading to asymmetrical deformation during operation and accelerating fatigue failure. Simultaneously, gas released from the hydraulic oil tends to accumulate at the top of the hydraulic chamber. If this gas is not promptly discharged, it will reduce hydraulic transmission efficiency, cause unstable diaphragm movement, and in severe cases, even lead to cavitation, damaging the diaphragm and the inner wall of the hydraulic chamber. Existing venting devices mostly employ manual or simple timed venting methods, failing to adaptively adjust the venting timing based on actual gas accumulation, resulting in inconsistent venting effectiveness. Furthermore, most existing diaphragms employ a uniform thickness and material design. Under cyclic pulse pressure loads, stress tends to concentrate in the transition area between the fixed edge and the moving center of the diaphragm, becoming a primary location for fatigue crack initiation. The diaphragm edge sealing area requires high stiffness to ensure sealing reliability, while the central working area requires lower stiffness to ensure sufficient deformation capacity. A uniform design cannot simultaneously meet these two conflicting stiffness requirements, limiting the improvement of the diaphragm's overall performance. The inherent periodic motion characteristics of reciprocating pumps cause their output flow to pulsate. Traditional single-chamber pneumatic dampers can only effectively suppress pulsation components near a single frequency, with limited effectiveness in suppressing broadband pulsations. Traditional commutation control mostly uses fixed timing or simple position feedback control. The commutation timing does not match the actual demand, and the sudden speed change of the piston at the end of its stroke generates a large pressure shock, leading to increased noise, vibration, and energy consumption, affecting the equipment's operational stability and service life.

[0004] Therefore, it is necessary to develop a new type of horizontal hydraulic diaphragm pump that can solve the above-mentioned technical problems. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a horizontal hydraulic diaphragm pump, comprising a power end, a hydraulic end, an auxiliary system, and a control system. The power end includes a drive motor, a crankshaft connecting rod mechanism, and a piston cylinder assembly. The hydraulic end includes a hydraulic chamber, a diaphragm, a diaphragm compartment, and an integrated intelligent venting device. The hydraulic chamber adopts an asymmetric gradually changing cross-section design, and the diaphragm is a gravity-compensated gradient stiffness composite diaphragm. The integrated intelligent venting device is disposed at the top of the hydraulic chamber. The auxiliary system includes a dual-chamber pre-pressure pulsation buffer. The dual-chamber pre-pressure pulsation buffer is connected to the pump's outlet pipe to absorb and smooth pressure pulsations generated during pumping. The control system includes multiple pressure sensors distributed along the axial direction of the hydraulic chamber and a central controller. The output terminals of the multiple pressure sensors are signal-connected to the input terminal of the central controller, and the output terminal of the central controller is signal-connected to the control terminal of the drive motor. The central controller is configured to perform pressure gradient adaptive commutation control based on the signals from the multiple pressure sensors.

[0006] Furthermore, the piston side of the hydraulic chamber has a circular cross-section, and the diaphragm side has an elliptical cross-section with the major axis of the ellipse set in the vertical direction. A gradual transition section is provided between the piston side and the diaphragm side. The top of the hydraulic chamber is provided with a spherical crown-shaped gas collection cavity, which is connected to the integrated intelligent exhaust device.

[0007] Furthermore, the diaphragm is disc-shaped and divided into an upper semicircular region and a lower semicircular region; the diaphragm is radially divided from the center to the edge into a central flexible region, a transition buffer zone, and an edge rigid region; a reinforcing skeleton is embedded in the transition buffer zone and the edge rigid region of the lower semicircular region.

[0008] Furthermore, the diaphragm has a multi-layer composite structure, comprising, from the medium side to the hydraulic oil side, the following components in sequence:

[0009] The working contact layer is a PTFE-modified fluororubber layer located on the medium-side surface of the diaphragm.

[0010] The main elastic layer is a hydrogenated nitrile rubber layer, located inside the working contact layer, and the reinforcing skeleton is embedded in the main elastic layer;

[0011] A fiber reinforcement layer, wherein the fiber reinforcement layer is an aramid fiber braided layer, located inside the main elastic layer, and the fiber direction of the fiber reinforcement layer is arranged in a cross pattern at ±45°;

[0012] An oil-side contact layer, which is an oil-resistant nitrile rubber layer, is located on the hydraulic oil side surface of the diaphragm and is bonded to the fiber reinforcement layer.

[0013] Furthermore, the total thickness of the diaphragm along the radial direction satisfies the following formula:

[0014] ;

[0015] in: The total thickness of the diaphragm at a radial distance r from the center is expressed in mm. The thickness of the central flexible region is expressed in mm. , where is the thickness of the edge rigid zone, in mm; r is the radial distance from the center of the diaphragm, in mm; denoted as diaphragm radius in mm; n is the gradient index.

[0016] Furthermore, the reinforcing skeleton includes multiple radial reinforcing ribs and an annular connecting band connecting each of the radial reinforcing ribs. Each of the radial reinforcing ribs is evenly distributed at an angle along the circumference, and the coverage area of ​​the reinforcing skeleton corresponds to the region of the diaphragm with a circumferential angle of 130° to 230°.

[0017] Furthermore, the integrated intelligent exhaust device includes a bubble gathering chamber, a gas-liquid separation microchannel group, a liquid level sensor, and an exhaust solenoid valve; the bubble gathering chamber is inverted conical in shape, and its bottom is connected to the spherical gas collecting cavity; the gas-liquid separation microchannel group is disposed above the bubble gathering chamber, including multiple microchannels evenly distributed along the circumference, and the inner wall of each microchannel is provided with an oleophobic and gas-friendly coating; the exhaust solenoid valve is disposed above the gas-liquid separation microchannel group, and the exhaust solenoid valve is a normally closed solenoid valve, whose control end is connected to the central controller and the liquid level sensor. When the liquid level sensor detects that the gas-liquid interface is lower than the set position, the central controller controls the exhaust solenoid valve to open.

[0018] Furthermore, the dual-chamber pre-compression pulsating buffer includes a main buffer chamber and an auxiliary buffer chamber; the main buffer chamber is equipped with an air bladder, and an inflation valve communicating with the air bladder is provided on the main buffer chamber; the auxiliary buffer chamber is equipped with a spring piston, and a preload adjusting screw is provided on the auxiliary buffer chamber, the preload adjusting screw abutting against the spring end of the spring piston; the main buffer chamber and the auxiliary buffer chamber are connected through a throttling orifice.

[0019] Furthermore, the plurality of pressure sensors includes a first pressure sensor disposed on the piston side of the hydraulic chamber and a second pressure sensor disposed on the diaphragm side of the hydraulic chamber; the central controller calculates the pressure gradient according to the following formula:

[0020] ;

[0021] in: This represents the axial pressure gradient of the hydraulic chamber, measured in MPa / m. The pressure value measured by the second pressure sensor is in MPa. The pressure value measured by the first pressure sensor is in MPa. The axial distance between the first pressure sensor and the second pressure sensor is expressed in meters (m).

[0022] The central controller calculates the pressure gradient change rate according to the following formula:

[0023] ;

[0024] in: The pressure gradient change rate is expressed in MPa / (m·s). This represents the pressure gradient at the current sampling time, in MPa / m. This represents the pressure gradient at the previous sampling time, in MPa / m. The sampling time interval is expressed in seconds (s).

[0025] When the pressure gradient change rate When the commutation conditions are met, the central controller controls the commutation speed according to the following formula:

[0026] ;

[0027] in: During the commutation process Piston velocity at any given moment; This is the maximum commutation speed; Pi; It is a cosine function; The time elapsed during the commutation process is expressed in seconds (s). The duration of the reversal is measured in seconds (s).

[0028] Furthermore, the control system also includes an outlet pressure sensor and a proportional regulating valve installed in the pump outlet pipeline. The output end of the outlet pressure sensor is connected to the input end of the central controller, and the output end of the central controller is connected to the control end of the proportional regulating valve.

[0029] The central controller is configured to perform iterative learning control, updating the compensation control signal according to the following formula:

[0030] ;

[0031] in: For the first Compensation control signal for each cycle; For the first Compensation control signal for each cycle; For learning gain; For the first The pressure error per cycle is expressed in MPa. For the periodic number;

[0032] The learning gain Adaptive adjustment is performed based on the error convergence, when the... The error norm of the nth period is less than that of the nth period. When the error norm is calculated for each period, the learning gain is adjusted according to the following formula:

[0033] ;

[0034] in: The adjusted learning gain; The function is for finding the minimum value; The learning gain before adjustment; This is the gain amplification factor; This represents the upper limit of the learning gain.

[0035] When the The error norm of the nth period is greater than or equal to that of the nth period. When the error norm is calculated for each period, the learning gain is adjusted according to the following formula:

[0036] ;

[0037] in: The adjusted learning gain; This is a function to find the maximum value. The learning gain before adjustment; This is the gain reduction factor; This is the lower limit of the learning gain;

[0038] The compensation control signal is output to the proportional regulating valve after D / A conversion, and the proportional regulating valve controls the connection area between the accumulator and the outlet pipe.

[0039] The beneficial effects achieved by this invention are as follows:

[0040] This invention designs a hydraulic cavity with an asymmetric gradually changing cross-section. The circular cross-section on the piston side gradually transitions to an elliptical cross-section on the diaphragm side, and a spherical cap-shaped gas collecting cavity is provided at the top. This avoids the generation of eddies or dead zones during the flow of hydraulic oil and provides a space for the natural convergence of gas precipitated in the hydraulic oil. This improves the pressure uniformity on the diaphragm surface and reduces excessive local deformation of the diaphragm caused by uneven pressure, laying a structural foundation for extending the service life of the diaphragm.

[0041] This invention employs a gravity-compensated gradient stiffness composite diaphragm, dividing the diaphragm radially into three functional regions: a central flexible region, a transition buffer zone, and an edge rigid region. Reinforcing skeletons are embedded within the transition buffer zone and edge rigid region in the lower semicircular area. The central flexible region uses a relatively thin thickness to ensure sufficient deformation capacity and achieve high volumetric efficiency. The thickness and stiffness of the transition buffer zone gradually change radially according to a power function, thus avoiding stress concentration caused by abrupt stiffness changes. The reinforcing skeleton is only arranged in the lower semicircular region of the diaphragm, compensating for the additional load caused by gravity in a horizontal arrangement. This makes the stress on the diaphragm more balanced throughout the entire working process, significantly improving the diaphragm's fatigue resistance and service life.

[0042] This invention features an integrated intelligent venting device at the top of the hydraulic chamber, comprising an inverted conical bubble-gathering chamber, a gas-liquid separation microchannel assembly with an oleophobic and gas-philic coating, a level sensor, and a normally closed venting solenoid valve. The inverted conical geometry of the bubble-gathering chamber allows bubbles to naturally converge upwards along the conical surface under buoyancy. The gas-liquid separation microchannel assembly, through its special surface coating, selectively allows gas to pass through while blocking hydraulic oil. The level sensor constitutes a dual detection mechanism to improve the reliability of venting triggering. When gas accumulation exceeds a threshold, the venting solenoid valve automatically opens to release the gas. After venting is complete, it automatically closes back to its normally closed state. The entire process requires no manual intervention, maintaining stable hydraulic transmission efficiency and avoiding unstable diaphragm movement and cavitation caused by gas accumulation.

[0043] This invention employs a dual-chamber pre-compression pulsation damper, comprising a main damper chamber with an internal air bladder and an auxiliary damper chamber with an internal spring piston, connected by a throttling orifice. The air bladder in the main damper chamber absorbs low-frequency, high-amplitude pulsations through elastic deformation, while the spring piston in the auxiliary damper chamber, with its faster response, is suitable for absorbing high-frequency, low-amplitude pulsations. The throttling orifice dampens the flowing liquid, dissipating pulsation energy. A preload adjusting screw on the auxiliary damper chamber adjusts the response characteristics of the spring piston, allowing the damper to adapt to different operating conditions. This dual-chamber series structure achieves wideband pulsation suppression, resulting in a more stable output flow, reduced pipe vibration and noise, and improved system operational stability.

[0044] The control system of this invention monitors the pressure gradient and its rate of change in real time using multiple pressure sensors distributed along the hydraulic cavity axis. Based on the characteristics of the pressure gradient rate of change, it predicts the optimal commutation time and implements soft commutation control using S-curve velocity planning. S-curve commutation ensures continuous and smooth acceleration changes, avoiding the impact force caused by sudden acceleration changes in traditional hard commutation. This reduces mechanical shock and vibration during commutation, lowers energy consumption, and extends equipment lifespan. Simultaneously, an iterative learning control algorithm is used to suppress outlet pressure pulsations. By recording and analyzing the error information of the previous cycle, the control signal for the next cycle is corrected and compensated. The learning gain is adaptively adjusted based on the error convergence, allowing the pressure pulsations to gradually converge to a minimum over multiple iterations. This achieves high-precision suppression of pressure pulsations and further improves the stability of the output pressure. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the overall structure of the horizontal hydraulic diaphragm pump of the present invention;

[0046] Figure 2 This is a cross-sectional schematic diagram of the diaphragm structure of the present invention;

[0047] Figure 3 This is a schematic cross-sectional view of the diaphragm layered structure of the present invention;

[0048] Figure 4 This is a cross-sectional structural diagram of the integrated intelligent exhaust device of the present invention;

[0049] Figure 5 This is a schematic cross-sectional view of the dual-cavity preloaded pulsating buffer of the present invention;

[0050] Figure 6 The figures are comparisons of the diaphragm fatigue life between Example 1 and Comparative Examples 1 and 2, where (a) is a comparison of fatigue life box plots and (b) is a comparison of failure mode distributions.

[0051] Figure 7 This is a comparison chart of the switching pressure characteristics of soft switching in Example 1 and hard switching in Comparative Example 1. (a) is a comparison chart of switching pressure waveforms, showing the change of hydraulic chamber pressure over time and the difference in peak values; (b) is a comparison chart of pressure change rate.

[0052] Figure 8 This is a comparison diagram of the flow pulsation suppression effect between the dual-cavity buffer of Example 1 and the single-cavity buffer of Comparative Example 1, where (a) is a comparison diagram of the flow time-domain waveform and (b) is a flow pulsation spectrum analysis diagram.

[0053] Figure 9The following is a diagram showing the effect of ILC pulsation suppression in Example 1: (a) is the ILC error convergence curve, showing the convergence process of the error norm with the iteration cycle; (b) is the adaptive learning gain adjustment curve, showing the dynamic adjustment process of the learning gain Γ; and (c) is a comparison diagram of the outlet pressure waveforms in the 1st and 50th cycles.

[0054] Figure 10 This is a radial distribution curve of the diaphragm thickness in Example 1, showing the comparison between the theoretical calculation value and the measured data points of the diaphragm thickness along the radial direction from the central flexible area, the transition buffer zone to the edge rigid area.

[0055] Numbering on the map:

[0056] 1. Hydraulic chamber; 11. Gradual transition section; 14. Spherical cap-shaped gas collecting cavity;

[0057] 2. Diaphragm; 21. Central flexible zone; 22. Transition buffer zone; 23. Edge rigid zone; 24. Reinforcing skeleton; 241. Radial reinforcing ribs; 242. Annular connecting strip; 26. Working contact layer; 27. Main elastic layer; 28. Fiber reinforcement layer; 29. ​​Oil side contact layer;

[0058] 3. Integrated intelligent exhaust device; 31. Bubble gathering chamber; 32. Gas-liquid separation microchannel group; 34. Liquid level sensor; 35. Exhaust solenoid valve;

[0059] 4. Dual-chamber pre-compression pulsating buffer; 41. Main buffer chamber; 42. Auxiliary buffer chamber; 43. Airbag; 44. Inflation valve; 45. Spring piston; 46. Preload adjusting screw; 47. Throttling orifice;

[0060] 5. Pressure sensor; 6. Central controller; 7. Outlet pressure sensor; 8. Proportional control valve; 9. Medium. Detailed Implementation

[0061] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] Reference Figures 1-5The horizontal hydraulic diaphragm pump provided by this invention comprises four main components: a power end, a hydraulic end, an auxiliary system, and a control system. The power end provides reciprocating driving force, the hydraulic end enables hydraulic transmission and media transport, the auxiliary system smooths output pulsations, and the control system enables intelligent operation control. The power end includes a drive motor, a crankshaft connecting rod mechanism, and a piston cylinder assembly. The drive motor is preferably a variable frequency speed-regulating motor, whose output shaft is connected to the crankshaft input end of the crankshaft connecting rod mechanism. The crankshaft connecting rod mechanism converts the rotational motion output by the drive motor into reciprocating linear motion, which is transmitted to the piston in the piston cylinder assembly via the connecting rod. The piston reciprocates within the piston cylinder, periodically compressing and releasing the hydraulic oil in the hydraulic chamber, thereby driving the diaphragm to reciprocate and deform.

[0063] The hydraulic end comprises a hydraulic chamber 1, a diaphragm 2, a diaphragm chamber, and an integrated intelligent venting device 3. The hydraulic chamber 1 employs an asymmetric gradually changing cross-section design to contain hydraulic oil and transmit the reciprocating motion of the piston to the diaphragm 2. The diaphragm 2 is a gravity-compensated gradient stiffness composite diaphragm, installed between the hydraulic chamber 1 and the diaphragm chamber, separating them. The diaphragm chamber is connected to the inlet and outlet pipes and is used to contain the medium to be transported. The integrated intelligent venting device 3 is located at the top of the hydraulic chamber 1 to automatically discharge accumulated gas within the hydraulic chamber 1.

[0064] The auxiliary system includes a dual-chamber pre-pressure pulsation buffer 4. The dual-chamber pre-pressure pulsation buffer 4 is connected to the pump's outlet pipe and is used to absorb and smooth the pressure pulsations generated during pumping, making the output flow more stable.

[0065] The control system includes multiple pressure sensors 5 distributed along the axial direction of the hydraulic chamber 1 and a central controller 6. The output terminals of the multiple pressure sensors 5 are connected to the input terminals of the central controller 6, and the output terminals of the central controller 6 are connected to the control terminals of the drive motor. The central controller 6 performs pressure gradient adaptive commutation control based on the signals from the multiple pressure sensors 5, thereby achieving smooth commutation and reducing commutation shock.

[0066] The structural design of hydraulic chamber 1 takes into account the influence of gravity on the distribution of hydraulic oil in a horizontal arrangement. The piston side of hydraulic chamber 1 has a circular cross-section, matching the piston of the piston cylinder assembly. The diaphragm side of hydraulic chamber 1 has an elliptical cross-section, with the major axis of the ellipse positioned vertically. A gradual transition section 11 is provided between the circular cross-section on the piston side and the elliptical cross-section on the diaphragm side, resulting in a smooth transition in cross-sectional shape and preventing eddies or dead zones from forming in the hydraulic oil during flow. The elliptical cross-section design compensates for the hydraulic oil column pressure borne by the lower part of the diaphragm in a static state, because the vertical stretching of the ellipse increases the cross-sectional area of ​​the lower region, thereby reducing the pressure load per unit area.

[0067] The top of the hydraulic chamber 1 is equipped with a spherical cap-shaped gas collecting cavity 14. Located at the highest point of the hydraulic chamber 1, the spherical cap-shaped geometry facilitates the natural aggregation of air bubbles. In a horizontal arrangement, dissolved gases in the hydraulic oil or accidentally introduced air bubbles will rise due to buoyancy and eventually accumulate within the spherical cap-shaped gas collecting cavity 14. The spherical cap-shaped gas collecting cavity 14 is connected to the integrated intelligent exhaust device 3, allowing the accumulated gas to be discharged in a timely manner.

[0068] The diaphragm 2 is the core working component of the hydraulic diaphragm pump, and its performance directly affects the pump's efficiency, lifespan, and reliability. The diaphragm 2 of this invention is a gravity-compensated gradient stiffness composite diaphragm, employing a special geometric design and a multi-layer composite material structure to adapt to the special stress conditions under horizontal arrangement.

[0069] The diaphragm 2 is disc-shaped, and its working diameter is determined according to the pump's flow requirements. Taking the center of the diaphragm 2 as the origin, and the horizontal direction to the right as 0°, with the clockwise direction representing the increasing angle, the diaphragm 2 can be divided into an upper semicircular region and a lower semicircular region. The upper semicircular region corresponds to a circumferential angle range of 0° to 180°, and the lower semicircular region corresponds to a circumferential angle range of 180° to 360°. In a horizontal arrangement, the lower semicircular region bears the additional gravitational load of the hydraulic oil, and its stress conditions are more demanding than those of the upper semicircular region.

[0070] The diaphragm 2 is radially divided into three functional regions from the center to the edge: a central flexible region 21, a transition buffer zone 22, and an edge rigid region 23. The central flexible region 21 is located in the central area of ​​the diaphragm 2, extending radially from the center to a certain proportion of the diaphragm radius R. This region uses a thinner thickness and a softer material formulation to ensure sufficient deformability, thereby achieving high volumetric efficiency. The transition buffer zone 22 is located between the central flexible region 21 and the edge rigid region 23. Its thickness and stiffness gradually change radially, serving as a stress transition and avoiding stress concentration caused by abrupt changes in stiffness. The edge rigid region 23 is located at the edge of the diaphragm 2, using a thicker thickness and embedding a reinforcing skeleton to achieve a reliable sealing connection with the diaphragm chamber, while also resisting edge roll-up deformation.

[0071] A reinforcing skeleton 24 is embedded within the transition buffer zone 22 and the edge rigid zone 23 of the lower semicircular region. The function of the reinforcing skeleton 24 is to enhance the load-bearing capacity of the lower semicircular region and compensate for the additional load caused by gravity. The reinforcing skeleton 24 is preferably made of glass fiber reinforced polyamide material, which has high tensile strength and good fatigue resistance, and also has good adhesive compatibility with the rubber matrix material of the diaphragm 2. The reinforcing skeleton 24 includes multiple radial reinforcing ribs 241 and annular connecting strips 242 connecting each radial reinforcing rib 241. Each radial reinforcing rib 241 is evenly distributed at an angle along the circumference, extending from the edge of the diaphragm 2 towards the center. The annular connecting strips 242 connect each radial reinforcing rib 241 into an integral grid structure, enhancing the overall stiffness and load-bearing capacity of the skeleton. The coverage area of ​​the reinforcing skeleton 24 corresponds to the region with a circumferential angle of 130° to 230° of the diaphragm, that is, within the lower 100° range of the diaphragm 2, which is the area where the influence of gravity is most significant under horizontal arrangement.

[0072] The diaphragm 2 has a multi-layered composite structure, comprising four functional layers from the medium side to the hydraulic oil side: a working contact layer 26, a main elastic layer 27, a fiber reinforcement layer 28, and an oil-side contact layer 29. This multi-layered composite structure allows each functional layer of the diaphragm 2 to perform its specific function and leverage the advantages of its respective materials, thereby achieving excellent overall performance.

[0073] The working contact layer 26 is a PTFE-modified fluororubber layer located on the media-side surface of the diaphragm 2, directly contacting the transported medium. PTFE, or polytetrafluoroethylene, is a polymer material with excellent corrosion resistance. By filling PTFE micropowder into the fluororubber matrix, the working contact layer 26 combines the elasticity of fluororubber with the corrosion resistance of PTFE. The thickness of the working contact layer 26 is determined according to the corrosiveness and abrasiveness of the medium, preferably ranging from 0.3 mm to 1.0 mm. The main function of this layer is to isolate the corrosive medium from eroding the internal structure of the diaphragm 2, extending the service life of the diaphragm 2.

[0074] The main elastic layer 27 is a hydrogenated nitrile butadiene rubber layer, located inside the working contact layer 26, and is the main structural layer of the diaphragm 2. Hydrogenated nitrile butadiene rubber is a modified rubber obtained by hydrogenating the unsaturated double bonds on the nitrile butadiene rubber molecular chain. It possesses excellent heat resistance, ozone resistance, and fatigue resistance, making it suitable for high-frequency reciprocating deformation working conditions. The thickness of the main elastic layer 27 constitutes the majority of the total thickness of the diaphragm 2, providing the necessary elastic deformation capacity for the diaphragm 2. The reinforcing skeleton 24 is embedded within the main elastic layer 27, forming a composite reinforcing structure with the hydrogenated nitrile butadiene rubber matrix.

[0075] The fiber reinforcement layer 28 is an aramid fiber braided layer located inside the main elastic layer 27. Aramid fiber is a high-strength, high-modulus organic fiber with excellent tensile strength and fatigue resistance. The fibers of the fiber reinforcement layer 28 are arranged in a ±45° cross pattern, meaning one layer of fibers is laid along the +45° direction and another layer is laid along the -45° direction, with the two layers overlapping each other. This ±45° cross arrangement gives the fiber reinforcement layer 28 a good reinforcement effect in all directions, effectively withstanding the multi-directional stress generated during the deformation of the diaphragm 2 and preventing the diaphragm 2 from cracking due to localized excessive stretching.

[0076] The oil-side contact layer 29 is an oil-resistant nitrile rubber layer located on the hydraulic oil side surface of the diaphragm 2, and is bonded to the fiber reinforcement layer 28. Nitrile rubber is a synthetic rubber with excellent oil resistance, capable of operating in a hydraulic oil environment for extended periods without swelling or performance degradation. The thickness of the oil-side contact layer 29 is preferably in the range of 0.3 mm to 0.8 mm, and its main function is to protect the internal structure of the diaphragm 2 from corrosion by the hydraulic oil, while providing a good contact interface between the diaphragm 2 and the hydraulic oil.

[0077] The total thickness of the diaphragm 2 along the radial direction follows a gradient change law, that is, it gradually increases in thickness from the central flexible region 21 to the edge rigid region 23. This thickness distribution law can be expressed by the following formula:

[0078] ;

[0079] in: Radial distance from the center Total thickness of the diaphragm at the location (mm); The thickness (mm) of the central flexible region 21; Thickness (mm) of the edge rigid zone 23; The radial distance (mm) from the center of the diaphragm. The diaphragm radius is (mm). This is the gradient index. Gradient Index The value of affects the rate of thickness gradient. When the value is large, the thickness increases more rapidly in the edge region. When the value is small, the thickness gradient is relatively gentle, which is the preferred value. The value ranges from 1.5 to 2.0. This power-law thickness distribution makes the thickness gradual change smooth and continuous, avoiding stress concentration caused by abrupt changes in thickness, thereby improving the fatigue life of diaphragm 2.

[0080] The preparation method of diaphragm 2 includes the following steps.

[0081] Step 1: Prepare the rubber compounds for each layer. For the working contact layer 26, mix fluororubber raw rubber with PTFE micro powder, vulcanizing agent, reinforcing filler, and other compounding agents according to the formula ratio to obtain a PTFE-modified fluororubber compound. For the main elastic layer 27, mix hydrogenated nitrile butadiene rubber raw rubber with vulcanizing agent, reinforcing filler, antioxidant, and other compounding agents according to the formula ratio to obtain a hydrogenated nitrile butadiene rubber compound. For the oil-side contact layer 29, mix nitrile butadiene rubber raw rubber with vulcanizing agent, reinforcing filler, and other compounding agents according to the formula ratio to obtain an oil-resistant nitrile butadiene rubber compound. The mixing process is preferably carried out in a Banbury mixer, and the mixing temperature and time are determined according to the type of rubber.

[0082] Step 2: Prepare fiber reinforcement layer 28. Aramid fibers are woven into a fiber cloth with a ±45° cross arrangement, or pre-fabricated aramid fiber fabric is cut at ±45° angles and then cross-layered. The fiber cloth is surface-treated to improve its adhesion strength to the rubber matrix. Surface treatment methods include, but are not limited to, resorcinol-formaldehyde-latex impregnation treatment or silane coupling agent treatment.

[0083] Step 3: Prepare the reinforcing skeleton 24. The glass fiber reinforced polyamide material is injection molded or machined to form a skeleton structure with radial reinforcing ribs 241 and annular connecting strips 242. The number of radial reinforcing ribs 241 is preferably 4 to 8, with the included angles between the ribs evenly distributed. The cross-sectional shape of the reinforcing ribs is preferably an isosceles trapezoid, which facilitates the mechanical anchoring bond between the skeleton and the rubber matrix. The molded reinforcing skeleton 24 requires surface activation treatment to improve its adhesion strength to the hydrogenated nitrile rubber main elastic layer 27.

[0084] Step 4: Sequentially load each layer of material and the skeleton assembly into the diaphragm molding mold for compression molding and vulcanization. First, lay the compounded rubber sheet of the oil-side contact layer 29 onto the surface of the mold's punch. Then, sequentially lay the compounded rubber sheets of the surface-treated fiber reinforcement layer 28 and the main elastic layer 27. Place the reinforcing skeleton 24 on the compounded rubber sheet of the main elastic layer 27, positioning it at a position between 130° and 230° in the corresponding lower semi-circular region. Continue laying the compounded rubber sheet of the main elastic layer 27 to cover the reinforcing skeleton 24, and then lay the compounded rubber sheet of the working contact layer 26.

[0085] Step 5: Close the mold and perform primary vulcanization. Place the molding mold on a flat vulcanizing machine and perform primary vulcanization according to the predetermined temperature, time, and pressure parameters. The purpose of primary vulcanization is to cause the layers of rubber material to cross-link and bond together into a whole. The vulcanization temperature is determined according to the type of rubber and the vulcanization system, the vulcanization time is determined according to the thickness of diaphragm 2 and the vulcanization temperature, and the vulcanization pressure should be sufficient to ensure that the mold closes completely and that the rubber fills every corner of the mold cavity.

[0086] Step 6: Perform secondary vulcanization. Remove the diaphragm 2 from the mold after primary vulcanization and place it in an oven for secondary vulcanization. The purpose of secondary vulcanization is to remove residual stress inside the diaphragm 2, making the vulcanization reaction more complete and further improving the mechanical properties and dimensional stability of the diaphragm 2. Secondary vulcanization uses a heat treatment method under free conditions; the temperature and time are determined according to the type of rubber.

[0087] Step 7: Inspect and trim the vulcanized diaphragm 2. Inspection includes visual inspection, dimensional measurement, and thickness uniformity testing. Trim any burrs on the edges of the diaphragm 2 to meet installation requirements. A qualified diaphragm 2 is then ready for use in the assembly of a horizontal hydraulic diaphragm pump.

[0088] The integrated intelligent exhaust device 3 is used to automatically discharge the gas accumulated in the hydraulic chamber 1. In a horizontal arrangement, dissolved air in the hydraulic oil or air bubbles that accidentally enter during system operation will rise due to buoyancy and accumulate at the top of the hydraulic chamber 1. If these gases are not discharged in time, it will lead to a decrease in hydraulic transmission efficiency, unstable diaphragm movement, and in severe cases, even cavitation.

[0089] The integrated intelligent exhaust device 3 includes a bubble gathering chamber 31, a gas-liquid separation microchannel group 32, a liquid level sensor 34, and an exhaust solenoid valve 35. The bubble gathering chamber 31 is inverted conical in shape, with its bottom connected to a spherical cap-shaped gas collecting cavity 14. The inverted conical geometry causes bubbles entering from the spherical cap-shaped gas collecting cavity 14 to converge upwards along the conical surface under the action of buoyancy, eventually accumulating at the top of the bubble gathering chamber 31. The cone angle of the bubble gathering chamber 31 is preferably in the range of 30° to 45°, which ensures effective bubble convergence while avoiding excessive retention of hydraulic oil. The volume of the bubble gathering chamber 31 is preferably 1% to 3% of the volume of the hydraulic chamber 1, which is sufficient to accommodate the amount of gas generated under normal operating conditions.

[0090] A gas-liquid separation microchannel assembly 32 is disposed above the bubble accumulation chamber 31 and includes multiple microchannels evenly distributed circumferentially. The inner wall of each microchannel is coated with an oleophobic and chemiphilic coating. This coating is a functional coating with special surface energy; its contact angle with gas is smaller than its contact angle with hydraulic oil, allowing gas to preferentially pass through the microchannel while hydraulic oil is blocked. The diameter of the microchannel is determined based on the viscosity and surface tension of the hydraulic oil, preferably ranging from 0.5 mm to 1.0 mm. Through the design of the gas-liquid separation microchannel assembly 32, selective gas passage can be achieved, avoiding hydraulic oil loss during the exhaust process.

[0091] The liquid level sensor 34 is used to detect the position of the gas-liquid interface in the bubble accumulation chamber 31. When the gas-liquid interface is lower than the set position, it indicates that a large amount of gas has accumulated in the bubble accumulation chamber 31, and the liquid level sensor 34 outputs a corresponding signal.

[0092] The exhaust solenoid valve 35 is positioned above the gas-liquid separation microchannel assembly 32 and is a normally closed solenoid valve. The control terminal of the exhaust solenoid valve 35 is connected to the liquid level sensor 34. When the liquid level sensor 34 detects that the gas-liquid interface is below a set position, the exhaust solenoid valve 35 opens, venting the gas from the bubble accumulation chamber 31. After exhausting, the exhaust solenoid valve 35 automatically closes, returning to its normally closed state. This dual-trigger mechanism improves the reliability of exhaust control and avoids exhaust failure caused by the failure of a single sensor.

[0093] The dual-chamber pre-pressure pulsation buffer 4 is used to absorb and smooth pressure pulsations generated during pumping. During operation, the output flow and pressure of a diaphragm pump exhibit periodic pulsations due to the reciprocating motion of the piston and the periodic opening and closing of the inlet and outlet valves. These pulsations are transmitted to the downstream pipeline system, causing pipeline vibration and noise, affecting the stable operation of the system.

[0094] The dual-cavity preloaded pulsation buffer 4 comprises two chambers: a main buffer chamber 41 and an auxiliary buffer chamber 42. The main buffer chamber 41 is used to absorb low-frequency large-amplitude pulsations, while the auxiliary buffer chamber 42 is used to absorb high-frequency small-amplitude pulsations. This dual-cavity structure enables the buffer to have good absorption effects on pulsation components of different frequencies, achieving wideband pulsation suppression.

[0095] An air bladder 43 is installed inside the main buffer chamber 41. The air bladder 43 is made of elastic rubber material and filled with compressed gas. An inflation valve 44 communicating with the air bladder 43 is provided on the main buffer chamber 41. The pre-charge pressure inside the air bladder 43 can be adjusted by the inflation valve 44 to match the working pressure of the pump. When the pipeline pressure increases, the air bladder 43 is compressed, absorbing part of the liquid volume, thereby reducing the pressure peak. When the pipeline pressure decreases, the air bladder 43 expands to release liquid and replenish the pressure trough. The elastic deformation of the air bladder 43 achieves the absorption and smoothing of pressure pulsations. The volume of the main buffer chamber 41 is preferably 0.5 to 1.0 times the pump's single-stroke displacement, which can effectively absorb the main pulsating components in the pumping cycle.

[0096] A spring piston 45 is installed inside the auxiliary buffer chamber 42. The spring piston 45 consists of a piston body and a return spring. The piston body can slide freely within the auxiliary buffer chamber 42, and the return spring provides preload to the piston body. A preload adjusting screw 46 is provided on the auxiliary buffer chamber 42, which abuts against the spring end of the spring piston 45. By adjusting the screw depth of the preload adjusting screw 46, the precompression of the return spring can be changed, thereby adjusting the response characteristics of the spring piston 45. The response speed of the spring piston 45 is faster than that of the airbag 43, making it suitable for absorbing high-frequency pulsating components. The volume of the auxiliary buffer chamber 42 is preferably 0.15 to 0.25 times the volume of the main buffer chamber 41.

[0097] The main buffer chamber 41 and the auxiliary buffer chamber 42 are connected by a throttling orifice 47. The throttling orifice 47 is a small-diameter through-hole whose function is to dampen the flowing liquid. When pressure pulsation occurs, the liquid flows between the main buffer chamber 41 and the auxiliary buffer chamber 42 through the throttling orifice 47. The damping force generated by the throttling orifice 47 on the liquid flow consumes the pulsation energy, further improving the pulsation suppression effect. The diameter of the throttling orifice 47 is determined according to the system flow rate and pulsation frequency; if it is too large, the damping will be insufficient; if it is too small, it will affect the liquid flow.

[0098] The control system of this invention employs a pressure gradient adaptive commutation control method to control the piston's commutation process. Traditional diaphragm pump commutation control typically uses fixed-sequence control or simple position feedback control. This control method cannot adapt to the optimal commutation timing under different operating conditions and is prone to commutation shock. This invention determines the commutation timing by monitoring changes in the pressure gradient within the hydraulic chamber 1 and uses S-curve speed control to achieve smooth commutation, thereby reducing commutation shock and extending equipment lifespan.

[0099] Multiple pressure sensors 5 include a first pressure sensor disposed on the piston side of the hydraulic chamber 1 and a second pressure sensor disposed on the diaphragm side of the hydraulic chamber 1. The first pressure sensor is mounted near the piston end face of the piston-cylinder assembly and is used to measure the pressure on the piston side of the hydraulic chamber 1. The second pressure sensor is installed near the diaphragm 2 and is used to measure the pressure on the diaphragm side of the hydraulic chamber 1. The sampling frequency of the two pressure sensors should meet the response requirements of the control system, preferably not less than 100Hz.

[0100] The pressure gradient adaptive commutation control method includes the following steps.

[0101] S1, Central Controller 6 calculates the pressure gradient according to the following formula: ;

[0102] in: The axial pressure gradient of the hydraulic chamber (MPa / m); The pressure value (MPa) measured by the second pressure sensor; The pressure value (MPa) measured by the first pressure sensor; The axial distance (m) between the first and second pressure sensors. Pressure gradient. This reflects the axial pressure distribution within hydraulic chamber 1. During the piston's thrust stroke, the piston-side pressure... Greater than the pressure on the diaphragm side pressure gradient It is a negative value. During the piston retraction stroke, the diaphragm-side pressure... Greater than piston side pressure pressure gradient It is a positive value. When the piston moves to near the end of its stroke, the pressure gradient is... The absolute value of reaches its maximum and then begins to decrease.

[0103] S11, Central Controller 6 calculates the pressure gradient change rate according to the following formula: ;

[0104] in: The pressure gradient change rate (MPa / (m·s)); The pressure gradient (MPa / m) at the current sampling time; The pressure gradient (MPa / m) at the previous sampling time. The sampling time interval (s). Pressure gradient change rate. This reflects the rate of change of the pressure gradient. As the piston approaches the end of its stroke, the rate of change of the pressure gradient changes significantly, and this change can be used as a basis for determining the reversing timing. Compared to traditional position detection, reversing timing determination based on the rate of change of the pressure gradient takes into account the actual dynamic response of the system, enabling more precise reversing control.

[0105] S12, when the pressure gradient change rate When the commutation condition is met, the central controller 6 initiates commutation control. The commutation condition can be set as the rate of change of the pressure gradient. Exceeding a preset threshold, or the rate of change of pressure gradient The sign changes. Meeting the reversing condition indicates that the piston has approached the end of its stroke and begun to decelerate, at which point the reversing process should be initiated.

[0106] S2, Central Controller 6 controls the commutation speed according to the following formula: ;

[0107] in: During the commutation process Piston velocity at any given moment; This is the maximum commutation speed; Pi; It is a cosine function; The time (s) during which the commutation process has been completed; Let be the commutation duration (s). This formula describes an S-shaped velocity curve, also known as a cosine acceleration / deceleration curve. At the start of the commutation... ,speed During the reversing process ,speed Reaching the maximum value At the end of the commutation ,speed Returning to 0. Compared with traditional linear acceleration and deceleration, the acceleration change of the S-curve commutation is continuous and smooth, avoiding the impact force caused by sudden acceleration changes, thereby reducing mechanical shock and vibration during the commutation process.

[0108] S21, The central controller 6 adaptively adjusts the commutation duration according to the current operating conditions. Commutation duration The choice needs to balance two factors: commutation smoothness and work efficiency. If the value is too large, the reversal process will take too long, affecting the pump's working efficiency; If the value is too small, the reversal process will be too fast, potentially causing a large impact. The central controller 6 can adjust the pressure gradient rate of change. Amplitude adaptive adjustment The switching time should be appropriately extended when the rate of change of the pressure gradient is large, and appropriately shortened when the rate of change of the pressure gradient is small.

[0109] The control system also includes an outlet pressure sensor 7 and a proportional control valve 8 installed in the pump outlet pipeline. The outlet pressure sensor 7 is used to measure the pump outlet pressure in real time. The output of the outlet pressure sensor 7 is connected to the input of the central controller 6. The output of the central controller 6 is connected to the control of the proportional control valve 8. The proportional control valve 8 is used to control the connection area between the accumulator and the outlet pipeline; by adjusting the connection area, real-time compensation for outlet pressure pulsations can be achieved.

[0110] Central controller 6 is configured to perform iterative learning control to suppress pressure pulsations at the pump outlet. Iterative learning control is a control method that utilizes the periodic motion characteristics of a system. Its basic idea is to record and analyze the error information of the previous motion cycle to correct and compensate the control signal for the next cycle, allowing the error to gradually converge over multiple iterations. The pumping process of a diaphragm pump has a natural periodicity; each piston reciprocating cycle generates a similar pressure pulsation waveform. This periodic characteristic provides the conditions for the application of iterative learning control.

[0111] The iterative learning-controlled pulsation suppression method includes the following steps.

[0112] S1. The central controller 6 acquires the pressure signal at the pump outlet through the outlet pressure sensor 7, filters the pressure signal to remove high-frequency noise, and identifies the start and end times of each pumping cycle through a cycle detection algorithm. The cycle detection algorithm can employ zero-crossing detection, extreme point detection, or other suitable methods. The pressure data within each cycle is stored for subsequent error calculation.

[0113] S11, the central controller 6 calculates the pressure error for each cycle. Let the... The measured pressure for each cycle is The target pressure is Then the first Pressure error per cycle for and The difference. Target pressure. The desired stable output pressure value is usually set, which can be a constant value or a variation curve set according to process requirements.

[0114] S2. The central controller 6 updates the compensation control signal according to the following formula: ;

[0115] in: For the first Compensation control signal for each cycle; For the first Compensation control signal for each cycle; For learning gain; For the first Pressure error per cycle (MPa); This represents the cycle number. This formula is the basic form of the P-type iterative learning control law, meaning that the error of the current cycle is multiplied by the learning gain and then superimposed onto the control signal of the current cycle to obtain the control signal for the next cycle. Through this error feedback and correction mechanism, the control signal gradually approaches the optimal value during multiple iterations, minimizing the pressure error. Learning gain The step size for error correction is determined. When the value is large, the convergence speed is faster, but oscillations may occur. When the value is small, the convergence speed is slower but the stability is better.

[0116] S21, Learning Gain Adaptive adjustment is performed based on the error convergence. This adaptive adjustment mechanism can accelerate convergence and improve control stability. When the... The error norm of the nth period is less than that of the nth period. When the error norm reaches a certain value over a certain number of cycles, it indicates that the error is converging. At this point, appropriately increasing the learning gain can accelerate the convergence speed. The central controller 6 adjusts the learning gain according to the following formula: ;

[0117] in: The adjusted learning gain; The function is for finding the minimum value; The learning gain before adjustment; This is the gain amplification factor; This represents the upper limit of the learning gain. The function for finding the minimum value. Its function is to limit the learning gain to an upper limit. Within a certain range, to prevent excessive learning gain from causing system instability. Gain amplification factor. The preferred value range is 1.02 to 1.10.

[0118] S22, when the When the error norm of the first period is greater than or equal to the error norm of the (k-1)th period, it indicates that the error may oscillate or diverge. In this case, the learning gain should be reduced to improve stability. The central controller 6 adjusts the learning gain according to the following formula: ;

[0119] in: The adjusted learning gain; This is a function to find the maximum value. The learning gain before adjustment; This is the gain reduction factor; This is the lower limit of the learning gain; This is the multiplication operator. The function to find the maximum value. Its function is to limit the learning gain to a lower limit. The above ensures that the control system has basic error correction capabilities. Gain reduction factor. The preferred value range is 0.7 to 0.9, which is less than the gain amplification factor. This asymmetric adjustment strategy enables the system to quickly reduce the learning gain to restore stability when the error diverges.

[0120] S3. The compensation control signal is output to the proportional control valve 8 after D / A conversion. D / A conversion, or digital-to-analog conversion, converts the digital control signal output from the central controller 6 into an analog voltage or current signal to drive the proportional control valve 8. The proportional control valve 8 adjusts the connection area between the accumulator and the outlet pipe according to the received control signal. When the outlet pressure is higher than the target pressure, the connection area is increased to allow some liquid to flow into the accumulator, reducing the outlet pressure. When the outlet pressure is lower than the target pressure, the connection area is decreased or the accumulator releases liquid, increasing the outlet pressure. Through this real-time adjustment, effective compensation for pressure pulsations can be achieved.

[0121] S31. When the error norm is less than the convergence threshold for several consecutive cycles, the iterative learning control is considered to have converged. After convergence, it enters steady-state holding mode, stops iterative updates, and directly uses the learned compensation control signal. Steady-state holding mode can reduce the computational load of the control system. When the operating conditions change and the error increases again, the central controller 6 detects the sudden increase in error, restarts the iterative learning process, and enables the control system to automatically adapt to the new operating conditions.

[0122] Example 1: This example provides a horizontal hydraulic diaphragm pump suitable for conveying slurry in mines, with a rated flow rate of 150 m³ / h. 3 / h, rated pressure 8MPa. The horizontal hydraulic diaphragm pump of this embodiment includes a power end, a hydraulic end, an auxiliary system, and a control system. The power end includes a 315kW variable frequency speed control drive motor, a crankshaft connecting rod mechanism, and a piston cylinder assembly. The crankshaft material is 42CrMo alloy steel, and the connecting rod material is 40Cr steel. Hydraulic chamber 1 structure: Hydraulic chamber 1 adopts an asymmetric gradually changing cross-section design. The piston side has a circular cross-section with a diameter of... The diaphragm side has an elliptical cross-section, with the major axis of the ellipse being... Set vertically, short axis The ratio of the major and minor axes of the ellipse A gradual transition section 11 is provided between the piston side and the diaphragm side, with a length of... It is 0.4 times the piston side diameter. The top of the hydraulic chamber 1 is provided with a spherical cap-shaped gas collecting cavity 14, the radius of which is... The diameter is 0.2 times that of the piston side. This spherical, crown-shaped gas collecting cavity 14 is connected to the integrated intelligent exhaust device 3. The hydraulic chamber 1 is made of 316L stainless steel, and its inner wall roughness is... Diaphragm 2 structure: Diaphragm 2 is disc-shaped with a working diameter of 400mm, divided into an upper semicircular region and a lower semicircular region. Diaphragm 2 is radially divided from the center to the edge into a central flexible region 21, a transition buffer zone 22, and an edge rigid region 23. The radial range of the central flexible region 21 is... ,thickness The radial range of the edge rigid region 23 is... ,thickness The radial range of the transition buffer 22 is... The thickness is calculated according to the formula. Gradient, Gradient Index A reinforcing skeleton 24 is embedded in the transition buffer zone 22 and the edge rigid zone 23 of the lower semicircular region of the diaphragm 2. The reinforcing skeleton 24 is made of glass fiber reinforced polyamide PA66-GF30 and includes 6 radial reinforcing ribs 241 and annular connecting strips 242 connecting each radial reinforcing rib 241. Each radial reinforcing rib 241 is evenly distributed at an angle along the circumference, and the coverage area of ​​the reinforcing skeleton 24 corresponds to the region of the diaphragm with a circumferential angle of 130° to 230°. The diaphragm 2 has a multi-layer composite structure, which includes the following layers from the medium side to the hydraulic oil side: the working contact layer 26 is a PTFE-modified fluororubber layer with a thickness of 0.4 mm and a PTFE micro powder content of 15 wt%; the main elastic layer 27 is a hydrogenated nitrile butadiene rubber (HNBR) layer with a thickness of 1.5–2.5 mm that gradually changes radially and a Shore hardness of 70 A, and the reinforcing skeleton 24 is embedded in the main elastic layer 27; the fiber reinforcement layer 28 is an aramid fiber braided layer with a thickness of 0.5 mm and the fiber direction is arranged in a cross pattern of ±45° with a surface density of 200 g / m²; and the oil side contact layer 29 is an oil-resistant nitrile butadiene rubber (NBR) layer with a thickness of 0.6 mm and an acrylonitrile content of 34%.

[0123] Integrated intelligent exhaust device 3: The integrated intelligent exhaust device 3 is located at the top of the hydraulic chamber 1 and includes a bubble gathering chamber 31, a gas-liquid separation microchannel group 32, a liquid level sensor 34, and an exhaust solenoid valve 35. The liquid level sensor 34 and the exhaust solenoid valve 35 are connected to the central controller 6. The bubble gathering chamber 31 is inverted conical with a cone angle of 40° and a volume of 150mL, which is 2% of the volume of the hydraulic chamber 1. Its bottom is connected to the spherical gas collecting cavity 14. The gas-liquid separation microchannel group 32 is located above the bubble gathering chamber 31 and includes 12 microchannels evenly distributed circumferentially. The microchannels have a diameter of 0.8mm, and the inner wall of each microchannel is coated with a fluorosilane-based oleophobic and anaerobic coating with a contact angle of 125°. The exhaust solenoid valve 35 is a normally closed solenoid valve with a diameter of DN8 and a response time of [missing information]. When the liquid level sensor 34 detects that the liquid level drops by more than 20 mm below the set position at the gas-liquid interface, the central controller 6 controls the exhaust solenoid valve 35 to open, and the exhaust time is 0.2 to 0.4 seconds.

[0124] Dual-chamber pre-compression pulsation buffer 4: The dual-chamber pre-compression pulsation buffer 4 is connected to the pump's outlet pipe. Main buffer chamber 41 volume... It has a displacement of 0.64 times that of a single-stroke 12.5L engine, and is equipped with a nitrile rubber airbag 43. The main buffer chamber 41 is equipped with an inflation valve 44 connected to the airbag 43, with a pre-charge pressure of 4.8MPa and 60% of the working pressure. The auxiliary buffer chamber 42 has a volume... The auxiliary buffer chamber 42 has a volume 0.19 times that of the main buffer chamber 41 and contains a spring piston 45 with a spring stiffness of 50 kN / m. The auxiliary buffer chamber 42 is equipped with a preload adjusting screw 46, which abuts against the spring end of the spring piston 45. The preload adjustment range is 2.4–8 MPa. The main buffer chamber 41 and the auxiliary buffer chamber 42 are connected by a throttling orifice 47 with a diameter of… It is approximately 0.2% of the cube root of the main buffer cavity volume of 2m.

[0125] Control System: The control system includes multiple pressure sensors 5 distributed along the axial direction of the hydraulic chamber 1 and a central controller 6. The pressure sensors 5 include a first pressure sensor located on the piston side of the hydraulic chamber 1 and a second pressure sensor located on the diaphragm side of the hydraulic chamber 1. The axial distance between the first pressure sensor and the second pressure sensor is... The sampling frequency is 200Hz, the measuring range is 0~20MPa, and the accuracy is ±0.1%FS. The output terminals of multiple pressure sensors 5 are connected to the input terminals of the central controller 6. The central controller 6 adopts a Siemens S7-1500 PLC, and the output terminals of the central controller 6 are connected to the control terminals of the drive motor.

[0126] The control system also includes an outlet pressure sensor 7 and a proportional control valve 8 installed in the pump outlet pipeline. The outlet pressure sensor 7 has a range of 0–16 MPa and an accuracy of ±0.25%FS. The proportional control valve 8 is a MOOGD633 series electro-hydraulic proportional valve with a flow range of 0–40 L / min. The central controller 6 is configured to perform pressure gradient adaptive commutation control based on signals from multiple pressure sensors 5, and to perform iterative learning control to suppress outlet pressure pulsation.

[0127] The working process is as follows: After the drive motor starts, the rotational motion is converted into the reciprocating linear motion of the piston through the crankshaft connecting rod mechanism. The piston reciprocates within the piston cylinder assembly, periodically compressing and releasing the hydraulic oil in the hydraulic chamber 1. During the discharge stroke: the piston moves towards the diaphragm side, the hydraulic oil pressure increases, and the pressure is transmitted to the diaphragm 2 through the gradual transition section 11 of the hydraulic chamber 1. Due to the elliptical cross-section design of the diaphragm side of the hydraulic chamber 1, the static pressure increment borne by the lower semicircular area of ​​the diaphragm 2 is compensated by the cross-sectional shape. At the same time, the reinforcing skeleton 24 of the lower semicircular area provides additional support through the radial reinforcing ribs 241 and the annular connecting strip 242, making the overall stress of the diaphragm 2 uniform. Under the action of hydraulic oil pressure, the diaphragm 2 deforms towards the medium cavity. The central flexible area 21 has the largest deformation, the transition buffer zone 22 achieves a smooth transition in stiffness, and the edge rigid area 23 maintains a seal. The working contact layer 26 is in direct contact with the slurry, the main elastic layer 27 provides elastic deformation, the fiber reinforcement layer 28 restricts excessive deformation, and the oil-side contact layer 29 is in contact with the hydraulic oil. The deformation of diaphragm 2 pushes the slurry in the medium chamber out through the discharge valve. During the suction stroke: the piston retracts to the piston side, the hydraulic oil pressure decreases, and diaphragm 2 recovers under the action of the medium chamber pressure and its own elastic restoring force, the volume of the medium chamber increases, and the slurry is sucked in through the feed valve.

[0128] Commutation control process: The central controller 6 acquires signals from the first and second pressure sensors in real time. and According to the formula Calculate the axial pressure gradient of the hydraulic chamber and according to the formula Calculate the rate of change of pressure gradient When the rate of change of the pressure gradient When the commutation conditions are met, the central controller 6 initiates S-curve soft commutation, according to the formula. Controlling commutation speed and commutation duration Maximum commutation speed It adapts and adjusts itself according to operating conditions.

[0129] Exhaust process: During the operation of hydraulic chamber 1, dissolved gases or accidentally introduced air bubbles rise due to buoyancy and converge into the bubble collection chamber 31 via the spherical gas collecting cavity 14. When the liquid level sensor 34 detects that the gas-liquid interface has dropped below the set threshold, the central controller 6 controls the exhaust solenoid valve 35 to open, and the gas is discharged through the gas-liquid separation microchannel group 32. After exhaust is completed, the exhaust solenoid valve 35 automatically closes.

[0130] Pulsation suppression process: Pressure pulsations generated during the pumping process are absorbed by the dual-chamber pre-pressure pulsation buffer 4. Low-frequency large-amplitude pulsations (0.5–5Hz) are absorbed by the air bladder 43 in the main buffer chamber 41, while high-frequency small-amplitude pulsations (5–50Hz) enter the auxiliary buffer chamber 42 through the throttling orifice 47 and are absorbed by the spring piston 45. The throttling orifice 47 exerts a damping effect on the fluid, consuming pulsation energy. Simultaneously, the central controller 6 performs iterative learning control according to the formula... Update the compensation control signal and learn the gain. The system adaptively adjusts based on the error convergence, and the compensation control signal is output to the proportional regulating valve 8 to control the connection area between the accumulator and the outlet pipeline, thereby achieving active compensation for pulsations.

[0131] Example 2: This example provides a large-scale high-pressure horizontal hydraulic diaphragm pump with a rated flow rate of 400 m³ / h. 3 / h, rated pressure 15MPa, drive motor power 1200kW.

[0132] The difference from Example 1 is that the piston side diameter of hydraulic chamber 1 is... The major axis of the ellipse on the diaphragm side short axis The ratio of the major and minor axes of the ellipse ; Length of the gradual transition section 11 ; spherical gas collecting cavity with a radius of 14 The diaphragm 2 has a working diameter of 600 mm, and the central flexible region 21 has a thickness of [missing information]. 23mm thickness of the edge rigid zone Gradient Index The reinforcing skeleton 24 includes eight radial reinforcing ribs 241. The main buffer cavity 41 has a volume... Airbag 43 pre-inflation pressure 9MPa; auxiliary buffer chamber 42 volume Spring stiffness 80kN / m; orifice diameter 47 The pressure sensor 5 has a sampling frequency of 300Hz and a measurement range of 0–25MPa. The remaining structure and operation are the same as in Example 1.

[0133] Example 3: This example provides a small horizontal hydraulic diaphragm pump with a rated flow rate of 50 m³ / h. 3 / h, rated pressure 5MPa, drive motor power 55kW. The difference from Example 1 is: the piston side diameter of hydraulic chamber 1... The major axis of the ellipse on the diaphragm side short axis The ratio of the major and minor axes of the ellipse ; Length of the gradual transition section 11 ; spherical gas collecting cavity with a radius of 14 The diaphragm 2 has a working diameter of 250 mm, and the central flexible region 21 has a thickness of [missing information]. 23mm thickness of the edge rigid zone Gradient Index The reinforcing skeleton 24 includes four radial reinforcing ribs 241. The main buffer cavity 41 has a volume... The airbag 43 has a pre-inflation pressure of 2.5 MPa; the auxiliary buffer chamber 42 has a volume of Spring stiffness 30kN / m; orifice diameter 47 The pressure sensor 5 has a sampling frequency of 100Hz and a measurement range of 0–10MPa. The remaining structure and operation are the same as in Example 1.

[0134] Comparative Example 1 uses a conventional circular cross-section hydraulic chamber and a uniform thickness diaphragm for comparison with Example 1. The difference from Example 1 is that both the piston side and diaphragm side of the hydraulic chamber have circular cross-sections with a diameter of 280mm, without a gradual transition section or a spherical cap-shaped gas collection cavity. The diaphragm adopts a uniform thickness design, with a thickness of 4.0mm across the entire diameter range, without radial partitioning or a reinforcing skeleton, and has a three-layer structure: a fluororubber layer + a canvas reinforcement layer + a nitrile rubber layer. No integrated intelligent exhaust device is provided; a manual exhaust valve is used. A single-chamber airbag-type pulsating buffer with a volume of 8L is used. Conventional hard reversing control is employed, without pressure gradient adaptive control and iterative learning control.

[0135] Comparative Example 2 uses an elliptical cross-section hydraulic cavity but without a gradient stiffness diaphragm design. It is used to compare and verify the improvement effect of the diaphragm structure with Example 1. The difference from Example 1 is that the hydraulic cavity structure is the same as that of Example 1, but the diaphragm adopts a uniform thickness design, with a thickness of 4.0 mm across the entire diameter range, no radial partitions, no reinforcing skeleton, and is a three-layer composite structure. The rest of the structure is the same as that of Example 1.

[0136] Comparative Example 3 employs a gradient stiffness diaphragm design but without an elliptical cross-section hydraulic cavity. It is used to compare and verify the improved hydraulic cavity structure with Example 1. The difference from Example 1 is that the diaphragm structure is the same, but both the piston side and diaphragm side of the hydraulic cavity have circular cross-sections with a diameter of 280 mm and no gradual transition section. The remaining structure is the same as Example 1.

[0137] Experimental Example 1: Diaphragm thickness distribution detection experiment;

[0138] Experimental objective: To verify the radial thickness distribution of the gradient stiffness composite diaphragm and to check the accuracy of the manufacturing process in achieving the design parameters.

[0139] Experimental method: Take the composite diaphragm sample prepared in Example 1, and use a digital micrometer (resolution 0.001 mm, accuracy ±0.002 mm) to measure radially from the center ( ) to the edge ( Measure the thickness at 10mm intervals, for a total of 21 measurement points. Each point is measured three times, and the average value is taken. Record the measured thickness data and compare it with the theoretical design value. contrast.

[0140] Experimental results: The experimental results are as follows Figure 10 As shown. From Figure 10 As can be seen, the theoretically calculated curve (blue solid line) exhibits a typical power function distribution characteristic, with the thickness increasing from the center. Smooth transition to the edge Conforms to the design formula The expected pattern. The 21 measured data points (red dots) show a high degree of agreement with the theoretical curve, with the maximum deviation being... relative error This indicates that the manufacturing process precision meets the design requirements.

[0141] The diagram clearly defines three functional areas: the central flexible area ( Thickness 3.0~3.8mm), transition buffer zone ( Thickness 3.8–4.8 mm) and edge rigid area ( (Thickness 4.8~5.5mm), with clear boundaries in each area and smooth transition of thickness gradient.

[0142] The slope of the curve increases with increasing radius (from...) The power exponent determines the thickness, indicating that the thickness variation in the edge region is more drastic, which matches the mechanical requirement that this region needs to withstand higher stress concentration.

[0143] This invention adopts The thickness distribution formula is obtained by controlling the gradient index. (This example) This achieves non-linear gradual change in thickness. Figure 10The measured data confirmed that the design could be precisely manufactured, laying the foundation for subsequent optimization of mechanical properties. Traditional uniform-thickness diaphragms, due to fixed edge constraints, experience severe stress concentration in the edge regions during operation, while the stress in the central region is relatively low, leading to uneven material utilization and premature edge failure. The gradient thickness design of this invention follows the principle of stiffness matching: increasing the thickness in the edge regions enhances bending stiffness to withstand high stresses, while decreasing the thickness in the central region maintains flexibility to accommodate large deformations. This design makes the stress / stiffness ratio of each region of the diaphragm more uniform, fundamentally eliminating stress concentration and extending the fatigue life of the diaphragm.

[0144] Experimental Example 2: Diaphragm fatigue life comparison experiment;

[0145] Experimental objective: To verify the advantages of gradient stiffness composite diaphragms over traditional uniform thickness diaphragms in terms of fatigue life, and to evaluate the impact of different structural designs on diaphragm service life.

[0146] Experimental methods: Ten diaphragm samples from each of Example 1 (gradient stiffness + elliptical cavity), Comparative Example 1 (traditional uniform thickness + circular cavity), and Comparative Example 2 (elliptical cavity + uniform thickness) were taken and fatigue tests were conducted on an accelerated life test bench (10MPa working pressure, 80 strokes / min stroke frequency, 60°C working temperature). The cumulative working time of each sample from the start of operation to failure was recorded, and the mean time to failure (MTTF) and failure mode distribution were statistically analyzed.

[0147] Experimental results: The experimental results are as follows Figure 6 As shown. From Figure 6 As shown in Figure (a), the median fatigue life of Example 1 is approximately 4850 hours, significantly higher than that of Comparative Example 1 (approximately 3050 hours) and Comparative Example 2 (approximately 3480 hours). Furthermore, the data distribution of Example 1 is more concentrated (the housing is narrower), indicating better performance stability. MTTF data shows that Example 1 achieves a 57.6% improvement compared to Comparative Example 1 and a 38.7% improvement compared to Comparative Example 2, quantitatively demonstrating the significant advantages of the gradient stiffness design and the synergistic effect of the elliptical cavity. From... Figure 6As shown in Figure (b), Example 1 is dominated by fatigue fracture (50%), which is a normal wear failure; Comparative Example 1 is dominated by edge tearing (35%), indicating severe stress concentration; Comparative Example 2 is dominated by surface cracking (35%), indicating that uneven pressure distribution leads to local overload. The failure modes show that the gradient stiffness design effectively eliminates edge stress concentration (edge ​​tearing decreased from 35% to 10%), and the elliptical cavity design improves the uniformity of pressure distribution (surface cracking decreased from 35% to 30%). The gradient stiffness composite diaphragm of this invention, combined with an adaptive pressure-balanced hydraulic cavity, can increase the diaphragm fatigue life by more than 57.6%, while transforming the main failure mode from early failure (edge ​​tearing) to normal wear failure (fatigue fracture), significantly improving the reliability of equipment operation.

[0148] Comparative Example 1, using a traditional circular cavity and a diaphragm of uniform thickness, had the shortest lifespan (3099h) and primarily failed due to edge tearing. Comparative Example 2, using an elliptical cavity and a diaphragm of uniform thickness, showed a slightly improved lifespan (3522h), but still primarily failed due to surface cracking. Example 1, using both an elliptical cavity and a gradient-thickness diaphragm, significantly improved the lifespan (4885h) and the failure mode shifted to normal wear. The elliptical cavity, through its gradual transition from a circular to an elliptical structure, disperses the pressure concentration area of ​​the discharge stroke from a single center point into a linear region along the major axis of the ellipse, reducing peak stress. The gradient-stiffness diaphragm, through edge thickening, improves the load-bearing capacity of high-stress areas. When the two work together, the elliptical cavity alters the spatial characteristics of stress distribution, while the gradient-stiffness diaphragm specifically matches this distribution, achieving dual optimization of load dispersion and stiffness matching.

[0149] Experiment Example 3: Reversing Pressure Characteristic Test Experiment;

[0150] Experimental objective: To verify the effect of pressure gradient adaptive commutation control method on suppressing commutation shock, and to evaluate the performance advantages of S-curve soft commutation strategy compared with traditional hard commutation.

[0151] Experimental Method: A Kistler 4075A high-frequency pressure sensor (response frequency 100kHz) was installed on the apparatus of Example 1 and Comparative Example 1, respectively, and hydraulic chamber pressure data during the reversing process was collected at a sampling rate of 10kHz. 100 reversing cycles were continuously collected for each group, and key indicators such as peak pressure and peak pressure change rate were calculated.

[0152] Experimental results: The experimental results are as follows Figure 7 As shown. From Figure 7As shown in Figure (a), Comparative Example 1 (red curve) exhibits a significant pressure spike (peak value 10.80 MPa) at the commutation moment, while Example 1 (blue curve) shows a smooth pressure transition within the commutation zone marked in yellow, with a peak value of only 8.32 MPa. Comparison of commutation zone time: The pressure abrupt change in Comparative Example 1 occurs within approximately 5 ms, while Example 1 achieves a smooth commutation through a 50 ms S-curve transition, a 10-fold increase in time but a significantly reduced impact. From... Figure 7 As shown in Figure (b), the peak pressure change rate of Comparative Example 1 reaches 710 MPa / s, forming a sharp pulse waveform; while the peak pressure change rate of Example 1 is only 185 MPa / s, with a smooth waveform and a decrease of 73.9%. From the waveform characteristics, it can be seen that the pressure curve of Example 1 is more stable throughout the entire working cycle, without obvious high-frequency oscillations, indicating that the S-curve reversal strategy effectively suppresses system vibration.

[0153] Experimental results show that the pressure gradient adaptive commutation control method of this invention can reduce the peak commutation pressure by 23.0% and the pressure change rate by 73.9%, effectively suppressing the impact load of commutation shock on the system and improving the stability and service life of the equipment. Traditional hard commutation control suddenly changes the hydraulic oil flow direction at the commutation moment, leading to a sudden pressure change; this invention adopts S-curve velocity planning, which reduces the pressure peak during commutation. According to The transition is smooth and regular. The essence of reversing impact is the sudden release of fluid kinetic energy in the hydraulic system. According to the water hammer effect formula... Pressure shock is directly proportional to the rate of velocity change. Traditional hard commutation results in a near-infinite rate of velocity change, generating strong pressure pulses. The S-curve commutation of this invention limits the rate of velocity change to a controllable range, fundamentally reducing the amplitude of pressure shocks. Simultaneously, the 50ms transition time allows sufficient time for fluid redistribution, preventing localized pressure buildup.

[0154] Experiment Example 4: Test Experiment on the Suppression Effect of Flow Pulsation;

[0155] Experimental objective: To verify the effect of the dual-cavity pulsation buffer on suppressing flow pulsation and to evaluate the performance advantages of the main-secondary cavity synergistic damping structure compared with the traditional single-cavity buffer.

[0156] Experimental Methods: Under the conditions of Example 1 (dual-cavity buffer), Comparative Example 1 (single-cavity buffer), and no buffer, outlet flow data were collected using an E+H Promag P300 electromagnetic flowmeter (accuracy ±0.2%) at a sampling rate of 1kHz. After continuously collecting data for 60 seconds, FFT spectrum analysis was performed to calculate the fundamental frequency (3Hz, three-cylinder pump) and the pulsation amplitude of each harmonic.

[0157] Experimental results: The experimental results are as follows Figure 8 As shown. From Figure 8 As shown in Figure (a), under the condition of no buffer (grey curve), the flow rate fluctuates drastically, with a peak-to-peak value of approximately ±23%; the single-chamber buffer (red curve) shows significant improvement but still exhibits considerable fluctuation (±11.8%); the dual-chamber buffer (blue curve) has the most stable waveform, approaching the ideal constant flow rate (±4.9%). All three curves revolve around an average flow rate of 150 m³ / h. 3 The fluctuation of / h (black dashed line) indicates that the buffer does not affect the average flow rate, but only suppresses the pulsating component. From Figure 8 As can be seen in Figure (b), at the 3Hz fundamental frequency (characteristic frequency of the three-cylinder pump), the amplitude without a buffer is the highest (17.5m). 3 / h), the single-chamber buffer decreased to 8.9m. 3 / h (reduced by 49%), dual-chamber buffer reduced to 3.7m 3 / h (reduced by 79%). The suppression effect of higher harmonics (6Hz, 9Hz) is more significant. The dual-cavity buffer has a suppression rate of 78% for the second harmonic and 78% for the third harmonic, indicating that the dual-cavity structure has a better filtering effect on high-frequency pulsation.

[0158] Experimental results show that the dual-cavity pulsation buffer device of this invention can reduce the flow pulsation rate from ±23.2% to ±4.9%, with a total suppression rate of 79%, which is a 61% improvement in suppression effect compared to the traditional single-cavity buffer (suppression rate 49%). In particular, it has a significant effect on suppressing high-order harmonics, effectively improving the flow stability of the system. Traditional single-cavity airbag buffers can only provide a single volume compensation function, with limited filtering effect on high-frequency pulsations; this invention adopts a composite structure of main cavity (airbag energy storage) + secondary cavity (spring damping) + throttling orifice. Figure 8 The spectral comparison directly proves the comprehensive suppression effect of this composite structure on frequency pulsations.

[0159] The main chamber uses a nitrogen-filled airbag (pre-pressurized to 4.8 MPa) to absorb low-frequency large-amplitude flow pulsations through the compressibility of the gas, which is equivalent to a low-pass filter. The secondary chamber uses a spring-piston structure (stiffness 50 kN / m) to absorb mid-frequency pulsations through the elastic deformation of the spring. The throttling orifice (diameter 4 mm) between the two chambers generates a pressure drop when fluid passes through, which consumes pulsation energy and forms a damping effect. The three mechanisms work together in different frequency ranges: the main chamber mainly targets the fundamental frequency (3 Hz), the secondary chamber mainly targets the first harmonic (6 Hz), and the throttling orifice mainly targets the higher harmonics (above 9 Hz). Figure 8 The dual-cavity buffer outperforms the single-cavity buffer across all frequency bands, demonstrating the effectiveness of the frequency division and coordination mechanism. From an energy perspective, pulsating energy is decomposed into: gas compression potential energy (main cavity) - spring elastic potential energy (secondary cavity) - fluid frictional heat energy (throttling orifice), achieving multi-stage absorption and dissipation of pulsating energy.

[0160] Experiment Example 5: Validation Experiment of Iterative Learning Control Effect;

[0161] Experimental objective: To verify the effect of the iterative learning control algorithm on suppressing pressure fluctuations, and to evaluate the convergence performance and steady-state accuracy of the adaptive learning gain adjustment strategy.

[0162] Experimental method: An iterative learning control algorithm was implemented on the device of Example 1, with a target pressure of 8 MPa and an initial learning gain. Gain amplification factor Gain reduction factor Upper limit of learning gain lower limit Run continuously for 50 cycles, and record the error norm for each cycle. and learning gain , as well as the complete pressure waveforms for the 1st and 50th cycles.

[0163] Experimental results: The experimental results are as follows Figure 9 As shown. From Figure 9 As shown in Figure (a), the error norm rapidly decreases from the initial 0.76 MPa, reaching below the convergence threshold (red dashed line, 0.15 MPa) around the 15th cycle, and then stabilizes within the range of 0.12–0.14 MPa, demonstrating the algorithm's good convergence. The convergence curve exhibits an exponential decay pattern, with the error decreasing most rapidly (approximately 70%) in the first 10 cycles, followed by a fine-tuning phase, consistent with the typical convergence characteristics of iterative learning control. Figure 9 As shown in Figure (b), the gain gradually increases from the initial value of 0.3 to near the upper limit of 0.5, with several instances of error bounce triggering a reduction adjustment. This demonstrates the robustness of the adaptive mechanism. From Figure 9 As shown in Figure (c), the pressure fluctuation range in the first cycle (red curve) is ±0.8 MPa, with the red-filled area representing the fluctuation range; in the 50th cycle (blue curve), the pressure fluctuation drops to ±0.12 MPa (blue-filled area), with the fluctuation range decreasing by 85%, almost reaching the ideal constant pressure output. The 85% reduction in pressure fluctuation shown by the yellow box is a quantitative indicator of the control effect.

[0164] Experimental results show that the iterative learning control algorithm of this invention can converge to steady state within 15 cycles, reducing pressure fluctuations from ±0.8MPa to ±0.12MPa, with a suppression rate of 85%. The adaptive learning gain adjustment mechanism improves system robustness while ensuring convergence speed, achieving high-precision pressure control. Traditional PID control relies solely on current error for feedback adjustment, failing to utilize the system's periodic characteristics; the iterative learning control algorithm of this invention memorizes error information from historical cycles and performs feedforward compensation. Figure 9The error convergence curve verifies the effectiveness of this learning mechanism. The operation of a diaphragm pump is highly repeatable; the motion trajectory and load distribution are essentially the same in each stroke cycle. Iterative learning control utilizes this characteristic to incorporate the tracking error from the previous cycle. This is added as a feedforward compensation signal to the control input of the current cycle: Learning gain The intensity of compensation is determined as follows: If it is too small, the convergence will be slow. Excessive gain may cause oscillation. The adaptive gain adjustment strategy of this invention achieves a dynamic balance between convergence speed and stability. From Figure 9 As can be seen in Figure (b), the gain increases rapidly in the early stage of convergence to accelerate learning, and decreases moderately to maintain stability when approaching steady state due to occasional disturbances. Figure 9 The waveform comparison in Figure (c) demonstrates the learning effect: the pressure curve in the 50th cycle is significantly narrower than that in the 1st cycle. This is because the controller has memorized the periodic disturbance pattern of the system through 50 iterations and actively cancels these disturbances through feedforward compensation. The 85% fluctuation suppression rate indicates that the iterative learning control successfully transforms disturbances that originally required passive response from feedback control into predictable and compensable periodic signals.

[0165] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A horizontal hydraulic diaphragm pump, comprising a power end, a hydraulic end, an auxiliary system, and a control system, characterized in that: The power unit includes a drive motor, a crankshaft connecting rod mechanism, and a piston cylinder assembly; The hydraulic end includes a hydraulic chamber, a diaphragm, a diaphragm chamber, and an integrated intelligent exhaust device. The hydraulic chamber adopts an asymmetric gradually changing cross-section design, the diaphragm is a gravity-compensated gradient stiffness composite diaphragm, and the integrated intelligent exhaust device is located on the top of the hydraulic chamber. The auxiliary system includes a dual-chamber pre-pressure pulsation buffer; the dual-chamber pre-pressure pulsation buffer is connected to the pump's outlet pipe to absorb and smooth pressure pulsations generated during pumping. The control system includes a plurality of pressure sensors distributed along the axial direction of the hydraulic chamber and a central controller. The output terminals of the plurality of pressure sensors are connected to the input terminal of the central controller, and the output terminal of the central controller is connected to the control terminal of the drive motor. The central controller is configured to perform pressure gradient adaptive commutation control based on the signals from the plurality of pressure sensors.

2. The horizontal hydraulic diaphragm pump according to claim 1, characterized in that: The piston side of the hydraulic chamber has a circular cross-section, and the diaphragm side has an elliptical cross-section with the major axis of the ellipse set in the vertical direction. A gradual transition section is provided between the piston side and the diaphragm side. The top of the hydraulic chamber is provided with a spherical crown-shaped gas collection cavity, which is connected to the integrated intelligent exhaust device.

3. The horizontal hydraulic diaphragm pump according to claim 1, characterized in that: The diaphragm is disc-shaped and divided into an upper semicircular region and a lower semicircular region. The diaphragm is radially divided from the center to the edge into a central flexible region, a transition buffer zone, and an edge rigid region. A reinforcing skeleton is embedded in the transition buffer zone and the edge rigid region of the lower semicircular region.

4. The horizontal hydraulic diaphragm pump according to claim 3, characterized in that: The diaphragm has a multi-layer composite structure, comprising, from the medium side to the hydraulic oil side, the following components in sequence: The working contact layer is a PTFE-modified fluororubber layer located on the medium-side surface of the diaphragm. The main elastic layer is a hydrogenated nitrile rubber layer, located inside the working contact layer, and the reinforcing skeleton is embedded in the main elastic layer; A fiber reinforcement layer, wherein the fiber reinforcement layer is an aramid fiber braided layer, located inside the main elastic layer, and the fiber direction of the fiber reinforcement layer is arranged in a cross pattern at ±45°; An oil-side contact layer, which is an oil-resistant nitrile rubber layer, is located on the hydraulic oil side surface of the diaphragm and is bonded to the fiber reinforcement layer.

5. The horizontal hydraulic diaphragm pump according to claim 3 or 4, characterized in that: The total thickness of the diaphragm in the radial direction satisfies the following formula: ； in: The total thickness of the diaphragm at a radial distance r from the center is expressed in mm. The thickness of the central flexible region is expressed in mm. , where is the thickness of the edge rigid zone, in mm; r is the radial distance from the center of the diaphragm, in mm; denoted as diaphragm radius in mm; n is the gradient index.

6. The horizontal hydraulic diaphragm pump according to claim 3, characterized in that: The reinforcing skeleton includes multiple radial reinforcing ribs and an annular connecting band connecting each of the radial reinforcing ribs. Each of the radial reinforcing ribs is evenly distributed at an angle along the circumference. The coverage area of ​​the reinforcing skeleton corresponds to the region of the diaphragm with a circumferential angle of 130° to 230°.

7. The horizontal hydraulic diaphragm pump according to claim 2, characterized in that: The integrated intelligent exhaust device includes a bubble gathering chamber, a gas-liquid separation microchannel group, a liquid level sensor, and an exhaust solenoid valve. The bubble gathering chamber is inverted conical in shape, and its bottom is connected to the spherical gas collection cavity. The gas-liquid separation microchannel group is located above the bubble gathering chamber and includes multiple microchannels evenly distributed circumferentially. The inner wall of each microchannel is provided with an oleophobic and gas-friendly coating. The exhaust solenoid valve is located above the gas-liquid separation microchannel group. The exhaust solenoid valve is a normally closed solenoid valve, and its control end is connected to the central controller and the liquid level sensor. When the liquid level sensor detects that the gas-liquid interface is lower than a set position, the central controller controls the exhaust solenoid valve to open.

8. The horizontal hydraulic diaphragm pump according to claim 1, characterized in that: The dual-chamber pre-compression pulsating buffer includes a main buffer chamber and an auxiliary buffer chamber; the main buffer chamber is equipped with an air bladder, and an inflation valve communicating with the air bladder is provided on the main buffer chamber; the auxiliary buffer chamber is equipped with a spring piston, and a preload adjusting screw is provided on the auxiliary buffer chamber, the preload adjusting screw abutting against the spring end of the spring piston; the main buffer chamber and the auxiliary buffer chamber are connected through a throttling orifice.

9. The horizontal hydraulic diaphragm pump according to claim 1, characterized in that: The plurality of pressure sensors includes a first pressure sensor disposed on the piston side of the hydraulic chamber and a second pressure sensor disposed on the diaphragm side of the hydraulic chamber; the central controller calculates the pressure gradient according to the following formula: ； in: This represents the axial pressure gradient of the hydraulic chamber, measured in MPa / m. The pressure value measured by the second pressure sensor is in MPa. The pressure value measured by the first pressure sensor is in MPa. The axial distance between the first pressure sensor and the second pressure sensor is expressed in meters (m). The central controller calculates the pressure gradient change rate according to the following formula: ； in: The pressure gradient change rate is expressed in MPa / (m·s). This represents the pressure gradient at the current sampling time, in MPa / m. This represents the pressure gradient at the previous sampling time, in MPa / m. The sampling time interval is expressed in seconds (s). When the pressure gradient change rate When the commutation conditions are met, the central controller controls the commutation speed according to the following formula: ； in: During the commutation process Piston velocity at any given moment; This is the maximum commutation speed; Pi; It is a cosine function; The time elapsed during the commutation process is expressed in seconds (s). The duration of the reversal is measured in seconds (s).

10. The horizontal hydraulic diaphragm pump according to claim 1, characterized in that: The control system also includes an outlet pressure sensor and a proportional regulating valve installed in the pump outlet pipeline. The output terminal of the outlet pressure sensor is connected to the input terminal of the central controller, and the output terminal of the central controller is connected to the control terminal of the proportional regulating valve. The central controller is configured to perform iterative learning control, updating the compensation control signal according to the following formula: ； in: For the first Compensation control signal for each cycle; For the first Compensation control signal for each cycle; For learning gain; For the first The pressure error per cycle is expressed in MPa. For the periodic number; The learning gain Adaptive adjustment is performed based on the error convergence, when the... The error norm of the nth period is less than that of the nth period. When the error norm is calculated for each period, the learning gain is adjusted according to the following formula: ； in: The adjusted learning gain; The function is for finding the minimum value; The learning gain before adjustment; This is the gain amplification factor; This represents the upper limit of the learning gain. When the The error norm of the nth period is greater than or equal to that of the nth period. When the error norm is calculated for each period, the learning gain is adjusted according to the following formula: ； in: The adjusted learning gain; This is a function to find the maximum value. The learning gain before adjustment; This is the gain reduction factor; This is the lower limit of the learning gain; The compensation control signal is output to the proportional regulating valve after D / A conversion, and the proportional regulating valve controls the connection area between the accumulator and the outlet pipe.

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