Hydraulic Valve Research Articles

Review of studies on the design optimization of hydraulic cartridge valves

Hydraulic cartridge valves are extensively used across numerous industries, attributed to their exceptional integration and potent flow capacity. To effectively address the varied load conditions, environmental influences, and durability demands in different contexts, it is crucial for designers to optimize these valves. Currently, a significant number of scholars have undertaken invaluable research on the design optimization of cartridge valves. The objective of this paper is to propose research concepts for the design optimization of hydraulic cartridge valves by analyzing the current literature and thereby boost the performance of hydraulic cartridge valve systems. This paper adopts a mixed review method, elaborating on the literature search methodology for reviews concerning cartridge valve design optimization. The obtained results are subjected to quantitative analysis. Following this, a thorough review of the identified literature is provided, focusing on the methodology and performance concerns of hydraulic cartridge valve design optimization. Finally, the prerequisites and challenges associated with the cartridge valve design optimization approach are discussed in detail, considering aspects such as compact lightweight design, reliability enhancement, and intelligent design optimization.

Correction: Avetissian et al. A Novel Piezoelectric Energy Harvester for Earcanal Dynamic Motion Exploitation Using a Bistable Resonator Cycled by Coupled Hydraulic Valves Made of Collapsed Flexible Tubes. Micromachines 2024, 15, 415

In the original publication [...]

Planning of a Single Flow Channel in Valve Blocks Based on Additive Manufacturing and the Ant Colony Algorithm

As electro-hydrostatic actuator (EHA) technology advances towards lightweight and integration, the demand for enhanced internal flow pathways in hydraulic valve blocks intensifies. However, owing to the constraints imposed by traditional manufacturing processes, conventional hydraulic integrated valve blocks fail to satisfy the demands of a more compact channel layout and lower energy dissipation. Notably, the subjectivity in the arrangement of internal passages results in a time-consuming and labor-intensive process. This study employed additive manufacturing technology and the ant colony algorithm and B-spline curves for the meticulous design of internal passages within an aviation EHA valve block. The layout environment for the valve block passages was established, and path optimization was achieved using the ant colony algorithm, complemented by smoothing using B-spline curves. Three-dimensional modeling was performed using SolidWorks software, revealing a 10.03% reduction in volume for the optimized passages compared with the original passages. Computational fluid dynamics (CFD) simulations were performed using Fluent software, demonstrating that the algorithmically optimized passages effectively prevented the occurrence of vortices at right-angled locations, exhibited superior flow characteristics, and concurrently reduced pressure losses by 34.09%–36.36%. The small discrepancy between the experimental and simulation results validated the efficacy of the ant colony algorithm and B-spline curves in optimizing the passage design, offering a viable solution for channel design in additive manufacturing.

Orifice erosion effect and variable gain control method for hydraulic servo spool valve

The hydraulic servo valve orifice becomes blunted due to erosion caused by solid particle contaminants in the oil, leading to a decline in the valve's static and dynamic performance. This study analyzes the working edge scanning model and proposes using a quarter-ellipse curve to fit the working edge contour for the precise calculation of the valve orifice area. Through AMESim simulation, this study investigates the relationship between valve orifice erosion and the static and dynamic characteristics of hydraulic servo slide valves and proposes a variable gain control method for addressing valve orifice erosion. Results show that the orifice area model based on the quarter elliptic curve is accurate. As erosion increases, the nonlinear area of the valve orifice curve expands, and the valve orifice degrades into a positive opening. The ratio of the long diameter to the short diameter of the ellipse is approximately linearly related to the pressure gain and leakage in the static characteristics of the hydraulic servo valve. After variable gain control, the static and dynamic characteristics of the servo valve closely resemble those of an ideal servo valve, with the maximum deviation between the flow characteristics and the ideal valve orifice approximately 1 %. Regarding pressure characteristics, the pressure drop before the zero position is below 0.2 MPa. This study establishes the internal relationship between orifice erosion and performance degradation and provides a novel approach to enhancing the erosion resistance of hydraulic servo valves.

Characterization of Hydraulic Spool Clamping Triggered by Solid Particles Based on Mechanical Model and Experiment Research

Hydraulic spool valves may clamp under the action of sensitive particles when working in hydraulic oils that contain solid particles, which will then bring about a devastating detriment to the machines. According to the failure statistics of hydraulic systems organized by ISO, more than 80% of the operational failures of hydraulic systems are caused by fluid contamination, and particulate contamination is the most important factor causing spool valve stagnation. In this paper, we considered various factors, including the material, size, and concentration of particles and the spool postures, and built a systematic spool clamping mechanical model. A device was designed to measure the spool valve friction under the action of particles. The influence of particle material, concentration, and size on the friction force of spool valves was investigated. By experiments, we measured the spool clamping force under the action of each single factor and then fitted the datum quantity of spool clamping force and the empirical equation of pulsating quantity. The study results demonstrate three types of non-ideal postures of spools in a valve hole, which are off-center, tilting, and off-center with tilting. Those three postures can engender clamping risk zones with different ranges inside the clearance between spool valves, increasing the risk of spool clamping. The kind of particles is found to have a certain but limited impact on the spool clamping force. Usually, particles with a higher elastic modulus can trigger a larger spool clamping force, which is in line with the theoretical equation. Within a certain range, the probability density distribution of particle size tallies with the normal distribution function, where the “sensitive particles” take up 0.7–1 of the clearance between spool valves. A higher particle volume fraction in oils means a greater number of sensitive particles and a larger spool clamping force. For the particles of a similar size with the clearance between spool valves, when their volume concentration tops over the “sensitive concentration”, namely 5%, the risk of spool clamping rises in a drastic manner. This study provides a theoretical reference and an empirical equation for the mechanism of spool clamping under the action of particles, as well as a definite quantitative indicator for the prediction and estimation of spool clamping which is of positive significance for the study of the predictive maintenance of hydraulic equipment.

Hydraulic valve design methodology for hydro turbine control system

The control of the turbine and its equipment in a hydroelectric power plant requires the HPU (hydraulic power unit) to deliver large volumes of working fluid in a short time at specific optimum control parameters. The use of typical proportional flow control valves created by manufacturers of hydraulic components in low-pressure control systems is disadvantageous due to high pressure losses in the control chambers. This paper presents the methodology and test results while designing a hydraulic proportional valve for low pressure and high flow rate operation. CFD (computational fluid dynamics) theory was analyzed and characteristic values were determined. The validation of CFD tests through those on the test bench was carried out, correction factor was determined. A new proprietary solution was developed and a series of simulation studies were carried out to determine the flow characteristics depending on the degree of the opening of the proportional flow control valve.

Structural optimization of hydraulic valve block based on generative design and selective laser melting process simulation

Structural optimization of hydraulic valve block based on generative design and selective laser melting process simulation

Improving the dynamic positioning accuracy of the electro-hydraulic drive

Research is focused on improving the dynamic accuracy of control surface positioning during the switching of hydraulic actuator modes and studying the processes and phenomena that cause control surface overshoot. Existing studies on the dynamic accuracy of hydraulic actuators have been analyzed. Transitional processes occurring in the " electromagnetic recirculation valve – electronic control unit" loop during changes in hydraulic actuator operating modes have been examined. The features of processes and physical phenomena leading to increased activation time of the hydraulic actuator have been identified. Solutions and electrical connection schemes for connecting the hydraulic actuator recirculation valve to the electronic control unit have been proposed to meet the accuracy positioning and activation time requirements. Experimental studies have been conducted to simulate the operational mode of hydraulic actuators, and failure situations modes under various load forces have been identified. Based on the results, principles for designing connection schemes for the electromagnetic recirculation valve of the hydraulic-mechanical actuator to the electronic control unit, which enhance system positioning accuracy at the structural level, have been formulated. Technical solutions aimed at achieving the specified accuracy and activation time for the hydraulic actuator have been developed and practically tested. The effectiveness and suitability of the proposed solutions for operational use, considering external factors, have been experimentally confirmed.

Investigation of Innovative High-Response Piezoelectric Actuator Used as Smart Actuator–Sensor System

This paper presents an experimental analysis of a high-response piezoelectric actuator system for the modular design of hydraulic digital fluid control units. It focuses on determining static and dynamic characteristics, forming the basis for developing a smart Industry 4.0 component that incorporates both actuator and sensor function. The design process examines the main challenges, advantages, disadvantages, and working principles to define parameters that impact the actuator’s behaviour and performance. The new piezoelectric actuator system features three piezoelectric stack actuators in series, enabling simultaneous actuation and sensing by applying and measuring the electrical voltage at each piezo element. The experimental setup and test methodology are explained in detail, revealing that the new design, combined with an appropriate open-loop or closed-loop control method, offers superior actuator stroke control, high stroke resolution, and a high-dynamic step response. This paper proposes a concept of a smart piezo actuator system focused on I4.0 and an actuator administration shell, integrated with 5G and RFID technology, which will allow automatic plug-and-play functionality and efficient interconnection, communication, and data transfer between the hydraulic valve and the piezoelectric actuator system.

Multi-objective optimization design of low-power-driven, large-flux, and fast-response three-stage valve

Intrinsically safe solenoids drive solenoid valves in coal mining equipment. The low power consumption of these solenoids limits the response time of the solenoid valves. Additionally, the low viscosity and high susceptibility to dust contamination of the emulsion fluid often lead to leakage and sticking of hydraulic valves. This study proposes a low-power-driven, large-flux, fast-response three-stage valve structure with an internal displacement feedback device to address these issues. The critical parameters of the valve were optimized using a novel multi-objective optimization algorithm. A prototype was manufactured based on the obtained parameters and subjected to simulation and experimental verification. The results demonstrate that the valve has an opening time of 21 ms, a closing time of 12 ms, and a maximum flow rate of approximately 225 L/min. The driving power of this structure is less than 1.2 W. By utilizing this valve for hydraulic cylinder control, a positioning accuracy of ± 0.15 mm was achieved. The comparative test results show that the proposed structural control error fluctuation is smaller than that of the 3/4 proportional valve.

Investigation on the Dynamic Characteristics of a New High-Pressure Water Hydraulic Flow Control Valve

Investigation on the Dynamic Characteristics of a New High-Pressure Water Hydraulic Flow Control Valve

A hybrid intelligent diagnostic approach for spool jamming faults of hydraulic directional valves

Directional valves are critical functional components in hydraulic systems for diverting the flow of hydraulic oil and controlling oil pressure. Faults of the valves could lead to failure and even serious accidents in hydraulic systems. Fault diagnostic accuracy is directly influenced by the effectiveness of signal processing. Due to the harsh operating environment of hydraulic systems, the condition monitoring signal acquired from the systems contains a large amount of redundant information and environmental noise. This makes the training processes of fault diagnostic approaches time-consuming and inefficient. In this paper, a new hybrid intelligent approach to spool jamming fault diagnostics for hydraulic directional valves is presented. The approach is designed based on the combined strengths of wavelet packet decomposition (WPD), empirical mode decomposition (EMD), variable mode decomposition (VMD), and the multi-layer perceptron (MLP) to improve the efficiency and accuracy of the fault diagnostic process. Five evaluation indices, including processing time (PT), local average accuracy (LAA), stability of accuracy (SA), weighted average of the neuron number (WANN), and robustness of WANN (ROB), are applied to benchmark the approach using ablation experiments. The experimental results show that the hybrid approach has a strong capability to extract fault-related features from the signal and perform fault diagnostics with high accuracy, efficiency, and robustness.

Physical model and Bayesian theory based hydraulic component fault diagnosis method

Hydraulic components are integral parts of hydraulic systems, and their failures directly impact the normal operation of hydraulic systems. Due to the dynamic variation of working pressure in hydraulic components with load, it is challenging to diagnose faults of hydraulic components under dynamic pressure conditions using existing methods. This paper focuses on the research of internal leakage faults in hydraulic directional control valves and proposes a fault diagnosis method based on physical model and Bayesian theory for hydraulic components. Firstly, this method investigates the working fault mechanism of hydraulic directional control valves and constructs an internal leakage model. Then, correlation analysis is introduced to select fault feature signals, and principal component analysis is adopted to construct internal leakage features. Finally, based on Bayesian model, Markov chain Monte Carlo sampling, and internal leakage features, the parameters of the internal leakage model are estimated to achieve fault diagnosis of internal leakage in hydraulic directional control valves. Experimental results demonstrate that compared to several traditional fault diagnosis methods, the proposed method exhibits higher adaptability and accuracy under dynamic pressure conditions. This method, based on the internal leakage model and Bayesian theory, realizes fault diagnosis of hydraulic components under dynamic pressure conditions, avoiding the shortcomings of deep learning methods that rely on a large amount of fault data to train fault models.

Research on Digitalization of Hydraulic Valves

The hydraulic pilot valve is an important component in hydraulic systems. Hydraulic systems and hydraulic control technology are the core of the development in the field of construction machinery. This article mainly introduces the concept and research significance of hydraulic valves, analyzes the current research status, level, and development trends at home and abroad, and is committed to researching, designing, and applying a hydraulic pilot valve with an electromagnetic positioning handle to improve the control performance of construction machinery.

Characteristic Progress and New Solutions for Nozzle Baffle Type Electro-Hydraulic Servo Valve

Background: This article outlines the working principle of the nozzle baffle type electro- hydraulic servo valve and analyzes the progress of research on its characteristics more fully. Objective: Firstly, it summarizes the research progress on the characteristics of the cavitation phenomenon, which is a common failure of nozzle baffle type electro-hydraulic servo valves; secondly, it comprehensively discusses the structural characteristics of nozzle baffle type electrohydraulic servo valves: moving-iron torque motors and moving-coil torque motors, as well as the progress of the research on the characteristics of the power-stage valve spools and direct-injection valve spools. Method: It suggests to the readers other optimization methods that can be made for the cavitation phenomenon in the future, and brings innovative ideas for the readers in terms of moving-iron vs. moving-coil torque motors and other aspects that can be improved for the power-stage spools vs. direct-injection spools. Again, for the typical technical problems of nozzle baffle type electrohydraulic servo valves, we have searched and organized the related technical patents at home and abroad and clearly outlined the current improvements for nozzle baffle type electro-hydraulic servo valves. Results: Through the discussion of related articles and patents, it is found that although many methods have been proposed at home and abroad to address the shortcomings of the nozzle baffle type electro-hydraulic servo valve, it still has a high failure rate and has not been comprehensively solved, there is still a lot of room for optimization. Conclusion: Finally, the new solutions proposed for the performance deficiencies of nozzle baffle type electro-hydraulic servo valves are summarized, and the future development trend of nozzle baffle type electro-hydraulic servo valves is predicted and outlooked.

Определение диссипативных потерь в гидравлическом приводе газораспределительного механизма двигателя внутреннего сгорания

Controlling the opening and closing times of intake and exhaust valves can improve the efficient parameters of an internal combustion engine and reduce the toxicity of combustion products. The valves are moved by an electronically controlled hydraulic drive. The energy consumption for the operation of a hydraulic valve drive is greater than when using a traditional mechanical drive. The dissipative energy losses in the accumulator one-way hydraulic valve drive are investigated. The working fluid of the hydraulic drive is SAE 5W-30 motor oil. The oil pressure behind the pump is 8 MPa, the diameter of the hydraulic cylinder is 16 mm. The main items of energy consumption are identified, and a methodology for their determination is proposed. The assessment of the efficiency of the hydraulic drive was based on the law of conservation of energy. To determine energy costs, a hydraulic drive model was compiled in the Simulink environment. A law of valve movement similar in shape to trapezoidal was obtained. The maximum speed of valve movement during the opening process is 4 m/s, during the closing process 3.8 m/s. During the period when the valve is held near the maximum lift of 14 mm, free oscillations with an amplitude of about 1 mm are observed. The energy consumption for a single actuation of the valve, which has a progressively moving mass of 0.5 kg, amounted to 25.9 J. Of this, a little more than 70% is spent on filling the hydraulic cylinder with liquid, the rest is spent when emptying it. As a result of throttling the fluid flow in the hydraulic cylinder rod stroke limiter and hydraulic brake, 56% of the energy is lost. Large energy losses are observed between the hydraulic accumulators and the hydraulic cylinder. When the cylinder is filled, 21.1% is lost here, and when it is emptied, 10.4%. Increasing the capacity of the supply and drain lines between hydraulic accumulators and hydraulic cylinders allows you to increase the speed of opening and closing valves. The main ways to increase the energy efficiency of the drive are to shift the hydraulic accumulators to the hydraulic cylinder, increase the diameter of the connecting lines, and increase the throughput of the solenoid valves.

Multi-objective optimization of a wet electromagnet-driven water hydraulic high-speed on/off valve for underwater manipulator in deep sea

Water hydraulic high-speed on/off valves (WHSVs) have the potential to replace the traditional oil hydraulic valves to be used in underwater hydraulic manipulators (UHMs) in the deep-sea environment due to their environmental friendliness, strong anti-pollution ability, and good sealing property. In this paper, we develop and optimize a novel wet electromagnet-driven WHSV to enhance its suitability for UHMs. Firstly, an accurate equivalent magnetic model of the WHSV is derived, considering the leakage flux and nonlinear characteristics. This magnetic model is combined with other physical field models to accurately describe the dynamic behavior of the WHSV and provide a comprehensive simulation framework. Then, the multi-objective optimization and decision-making methods are combined to optimize and determine the structural parameters of the WHSV, achieving a balance between rapid response and light mass. Finally, a WHSV prototype is manufactured and tested based on the optimized structural parameters. Experimental results indicate that the WHSV achieves opening and closing times of 1.63 ms and 1.22 ms, respectively, with the electromagnetic components weighing 75.5 g. These results show a maximum deviation of 7.4 % from the optimization results (1.52 ms, 1.31 ms, 71.6 g). Moreover, the deep-sea simulation test verifies the prototype functionality under a high-pressure condition (110 MPa).

A Twice-Open Control Method for a Hydraulic Variable Valve System in a Diesel Engine

In order to solve the cold-starting problem and improve the intake and exhaust pipe temperatures of diesel engines under cold-starting and low- and medium-speed conditions, this paper proposes a twice-open control method for a hydraulic variable valve system. First, a hydraulic variable valve system that can realize a fully variable valve lift and phase angle is applied to replace the original intake system in order to meet the air intake requirements of different conditions. Then, a twice-open control method in which the intake valve opens two times at the exhaust stroke and intake stroke is proposed to improve the intake pipe temperature and solve the cold-starting problem. This paper contains a numerical work analysis. A GT-POWER model is constructed to validate the intake valve twice-open control method. The cylinder pressure, cylinder temperature, intake pipe pressure, and intake pipe temperature are obtained and compared between the original intake valve system and the hydraulic variable valve system with the proposed intake valve twice-open control method. The results show that the twice-open control method can increase the intake pipe temperature to 260 K or even higher, which can improve the cold-starting performance and the exhaust temperature at low and medium speeds. At the same time, the performance under low- and medium-speed conditions is improved.

Path integration solutions for stochastic systems with Markovian jumps

A path integration method for solving Markovian jump stochastic dynamical systems is presented. The Markovian jump process and the state vector of the system are combined into a new augmented state vector. The randomness of the Markovian jump is modeled by a stochastic process, which is merged with the stochastic perturbations to form the stochastic source affecting the evolution of the augmented system. Then a probability mapping is constructed, mapping the probability space of the stochastic source to the short-time transition probability density function of the augmented system. By solving this probability mapping, the short-time transition probability density function of the path integration method is obtained, thus a path integration method is customized for Markovian jump stochastic systems. Finally, a hydraulic relief valve system is used as an application example to demonstrate the availability of the path integration algorithm. The results suggest that the pre-compression parameters and coefficient of restitution of the plug can induce stochastic P-bifurcation phenomena. When the above two parameters are small, the system becomes unstable with the parameters taken in this example. Monte Carlo simulations prove that the proposed method effectively captures the transient and stationary responses of Markovian jump systems.

Dynamic analysis and optimization of a novel Dual-valve heave compensator for heavy lifting operations

Traditional Passive Heave Compensator (PHC) requires set parameters before operation according to the specific sea conditions, making it difficult to adapt to complex and variable working environments. This study aims to enhance the environmental adaptability of classical PHC by proposing a novel concept of Dual-valve Heave Compensator (DHC) based on the traditional PHC framework. By modulating the hydraulic and pneumatic throttle valve openings dynamically, the DHC system facilitates adjustments extensively in damping and stiffness, significantly enhancing compensation performances. As an enhancement over traditional models, this study incorporates a coupled dynamic model that accounts for critical influencing factors, including gas temperature and nonlinear friction. A linearized equation for the dynamic stiffness of DHC has been developed based on the small deviation linearization method, extensively analysing the effects of pneumatic parameters on the stiffness characteristics. Furthermore, a design framework employing Latin Hypercube Sampling (LHS) design, Radial Basis Function (RBF) surrogate model, and Non-dominated Sorting Genetic Algorithm-II (NSGA-II) has been specifically developed to address the multi-objective optimization challenges presented by DHC systems. The case study indicates that the optimized DHC can achieve up to 86% compensation accuracy under a 250-ton load with harmonic excitation and offers adjustments flexibly for various operational conditions. Contrary to conventional wisdom, minimal valve openings significantly enhance compensation accuracy during some intervals of irregular wave excitation. These findings confirm the superior performance and potential of DHC relative to traditional PHCs under complex marine environments.