Hydraulic Vane Pump Research Articles

The Effect of Bias Voltage and Acetylene Gas Flow Rate on the Wear Behavior of Diamond-like Carbon Coatings on M2 High-Speed Steel

This paper investigates the impact of bias voltage and acetylene flow rate on the mechanical, structural, and scratch performance of diamond-like carbon (DLC) coated high-speed steel (HSS) M2 commonly used in hydraulic vane pumps. The DLC coatings were produced through plasma-enhanced chemical vapour deposition, with micro-Raman spectroscopy used to analyze their structure via G-peak and D-peak measurements. Results showed that DLC deposited at 350 V and 100 sccm demonstrated high hardness (28.99 GPa) and modulus of elasticity (308.1 GPa), with the highest critical load of 167.246 mN indicating superior adhesion to the HSS M2 substrate at a higher bias voltage and lower flow rate. The minimum wear rate of 3.02 × 10−3 mm3/Nm was achieved with a thinner DLC coating deposited at 350V bias voltage and 100 sccm acetylene flow rate.

Stator Curvature Optimization and Analysis of Axial Hydraulic Vane Pumps

Aiming at the problem of large vibration of a high-subside stator inner cavity curve vane pump, the force analysis of the vane at the transition curve is carried out, and the functional relationship between the vane turning angle θ, the large arc radius R, the small arc radius r and the sliding friction is established. The particle swarm algorithm is used to optimize the solution of the objective function, and the optimized parameter values are brought into the MATLAB simulation program to obtain the optimized stator curve profile diagram. The dynamic performance of the vane pump before and after optimization is simulated using ADAMS. The results show that: the acceleration of the vane pump slide is significantly reduced; the friction between the slide and the slide groove is significantly reduced; the contact force between the slide and the stator is significantly reduced; the impact vibration of the optimized vane pump is significantly reduced; and the dynamic performance of the vane pump is improved.

Hydraulic pump automatic test system based on C/S structure

In order to meet the automation production and testing needs of modern enterprises, this paper takes the hydraulic vane pump test bench as an example, and builds a set of hydraulic automatic measurement and control system based on C/S framework, which can meet the requirements of single/double pump test simultaneously. Among them, the client software is developed based on LabVIEW, the server is built based on FTP protocol and MYSQL database, and the test bench is successfully connected to the internal production management system of the enterprise through the local area network, realizing the integration of product model management, process control, automatic testing, result uploading and other functions. At the same time, the PID closed-loop control strategy was improved in the acceleration and loading stages to shorten the test time and reduce the system overshoot. Finally, the automatic run-in, efficiency verification and low-speed pressure-holding test of vane pump have been completed.

Analysis of vane loads and motion in a hydraulic double vane pump with integrated electrical drive

In this paper, the results of the analysis of the forces acting on vanes in a double-acting vane pump with an integrated electric drive have been presented. In the new motor pump unit, the pump is assembled inside the rotor of the electric motor. A dynamic model representing the vane movement has been developed considering the impact of pressure load distribution, vane support forces and friction forces. The loss of contact between the vane head and the cam ring lead to the noise and reduction of the volumetric pump efficiency. The dynamic model which describes the vane motion and contact between the vane tip and cam ring has been solved using MATLAB software. The influence of load distribution, pump design and operational parameters on the vane dynamics has been analysed.

The Cavitation Characteristics of Oil Hydraulic Vane Pumps

The Cavitation Characteristics of Oil Hydraulic Vane Pumps

Vibration and temperature variation of the cam ring of a hydraulic vane pump associated with vane tip detachment

Vibration and temperature variation of the cam ring of a hydraulic vane pump associated with vane tip detachment

Behavioral characteristics of the vane of a hydraulic vane pump for power steering systems

In an oil hydraulic vane pump for power steering systems, the force acting on the vane generally consists of oil hydraulic, inertial and viscous forces. The vane should not separate from the camring inner race during operation. Separation of the vane could occur during the initiation and delivery of the vane pump because the oil hydraulic force acting on the vane is zero and in equilibrium, respectively. If the vane is separated from the camring inner race, the delivery of the oil hydraulic vane pump could become unstable or volume efficiency could decrease rapidly. Therefore, the state of the contact between the vane and the camring is considered in this study. Results demonstrate that the rotating speed of the shaft, oil temperature, clearance between the vane and the rotor and mass of the vane significantly affect the contact state of the vane.

A study on flow control valve characteristics in an oil hydraulic vane pump for power steering systems

In the power steering system of an automobile, the balanced and fixed displacement type vane pump is principally applied to the main power source. It is driven by a pulley that is attached to the shaft of the vehicle's engine, and the pulley ratio is about 1:1. The vane pump continuously discharges an outlet flow rate proportional to the rotating speed of the engine. In a vane pump without the flow control valve, an increase in the discharge flow rate means a linear increase in the actuator speed. At high speed when the driver rotates the steering wheel by even a small amount, there is a high risk of an accident due to the quick rotation of the tire joined to the actuator and links. We designed a flow control valve of the fixed displacement and pressure balanced type vane pump for power steering is designed and simulated using AMESim software. Its theoretical flow characteristics with respect to the rotating speed of the engine are compared and validated with experimental data. The results show that the design parameters, such as the flow area, the underlap length, the spool clearance, the main spring stiffness and the spring initial force, largely affect the flow control characteristics.

Theoretical and Experimental Research on a Pressure-Reducing Valve for a Water Hydraulic Vane Pump

In order to control the high PV value between the vanes and the cam ring in a water hydraulic vane pump, a pressure-reducing valve with a constant pressure ratio was developed in this study. The pressure and leakage characteristics of the valve were theoretically analyzed by simulation and the experiments were also conducted based on the valve prototype. The theoretical analysis agrees well with the experimental results. Further, these results reveal that the pressure ratio of the valve decreases to the design value with the increasing working pressure. Additionally, the leakage of the valve rises simultaneously with the increasing working pressure and can be reduced significantly by decreasing the clearance between the valve body and the spool. The presented research not only proves the successful development of the pressure-reducing valve but also lays a foundation for the investigation of a high-pressure water hydraulic vane pump.

Optimization and Simulation on Pressure-Reducing Valve in Water Hydraulic Vane Pump

High contact stress between the vane tips and the cam ring is one of the main obstacles to improve the working pressure of a water hydraulic vane pump. A pressure-reducing valve for regulating the bottom pressure of the vanes at the pump suction zone is presented in this paper. Through optimization and simulation, it is found that the throttle structure has great influence on the dynamic performance of the pressure-reducing valve, and the triangular-rectangular groove is proved to be more suitable for the valve among all the investigated grooves. The theoretical analysis results show that the use of the pressure reducing valve can obviously reduce the contact forces between the cam ring and the vanes at the suction zone of the pump. The work in this research provides a feasible solution to improve the working pressure of a water hydraulic vane pump.

유압 베인 펌프에서의 탄성유체윤활 해석

Hydraulic vane pumps are widely used in various hydraulic systems because of its compactness and light weight. It is well known that the vanes and cam ring are separated by very thin liquid films which result in the EHL state. Contrary to the case of cylindrical roller bearings, the inlet and side boundary pressures are much higher than the atmospheric pressure. In this paper, a numerical solution of the EHL of finite line contacts between the cam ring and vane tip with profiled ends is presented. Using a finite difference method with non-uniform grids and the Newton-Raphson method, converged solutions are obtained for moderate load and material parameters. The EHL pressure distribution and film shape are considerably affected by pump delivery pressure and the side boundary condition applied. Both the maximum pressure and the minimum film thickness always occurred near the edge regions. The present results can be used in the design of optimum vane profile in hydraulic vane pump.

The Inertia Force of the Vanes in the Hydraulic Vane Pump with Advanced Hypertrochoid Curve in the Inner Surface of its Stator

The possibility of application of the advanced hypertrochoid curve in the inner surface of the stator of fixed displacement hydraulic vane pump, theoretically was studied in the last our work. By considering the properties of this curve, sealing action between pressure and suction sides of the pump can be improved. One of the important characteristics of a new profile must be improving of the inertial reaction of the vanes in each position where these vanes have a radial movement because it causes a smooth sliding motion of the vanes, and hence, a higher performance of the pump while attaining a longer life of it. Then at this paper, the effect of the inertial force of the vanes on the performance of the pump with this curve will be studied. The regular motion of the vanes on the inner surface of the stator with smooth profile suppresses the lateral reactional force applied to the vanes and results to diminish local wear of the vanes tip and noise.

A Theoretical Study of the Internal Forces in a Hydraulic Vane Pump with Hypertrochoid Curve in the Inner Surface of its Stator

In the latest our works, Performance of a fixed displacement- hydraulic balance vane pump, theoretically and practically was studied by application of the basic hypertrochoid curve in the inner surface of its stator. Also the effect of the inertia force of the vanes on the performance of the pump with this curve was studied. This study presents a theoretical analysis of the internal pressure distribution in the pump, and of the resulting forces and torques applied to its components. This analysis is essential to the study of the pump dynamics and control, the pump design, and selection of the pump bearings. These forces are shown to be a function of the line pressure, the shaft rotational speed, the fluid bulk modulus, the fluid viscosity, and the design geometry. These forces are composed of two components: a continuous component due to the exposure of chambers to the line port, and an intermittent component due to a hydraulic lock phenomenon.

A Study of the Effect of the Inertia Force of the Vanes on the Performance of the Hydraulic Vane Pump with Hypertrochoid Curve in the Inner Surface of its Stator

Performance of a fixed displacement hydraulic balance vane pump, theoretically and practically was studied by application of the hypertrochoid curve in the inner surface of its stator. In addition to improving a sealing action between pressure and suction sides of the pump, one of the important characteristics of the hypertrochoid profile is improving of the inertial reaction of the vanes in each position where these vanes have a radial movement. Then it causes a smooth sliding motion of the vanes, and hence, a higher performance of the pump while attaining a longer life of it because of decreasing vane- tip and inner surface of stator wear and decreasing of vibration, noise and high stresses.

Characteristics of PAG Based Bio-Hydraulic Fluid

Abstract Regulatory drivers both in the U.S. and in the European Union are attempting to promote the use of biodegradable lubricants in the marketplace. A base fluid that uses the first ever combination of biodegradable polyalkylene glycol (PAG) with a high oleic canola oil was developed to meet environmental accreditation standards. This combination utilizes the PAG to “upgrade” the vegetable oil in hydraulic fluid formulation and provide a base fluid that can solubilize the oxidation by-products and provide better deposit control compared to straight general purpose fluids that are based on vegetable oils. A general purpose bio-hydraulic fluid that use a blend of PAG and high oleic canola oil has shown enhanced performance characteristics in two critical tests namely an oxidation test (ASTM D 2893 B) and a hydraulic vane pump test (ASTM D 7043). These two tests clearly differentiate the superior attributes of the PAG-based bio-hydraulic fluid compared to a widely use general purpose biodegradable hydraulic fluid in the market place.

Studies on several key problems of water hydraulic vane pump

PurposeThe balanced vane pump is a common transmission component in hydraulic systems. Since the physicochemical properties of water and seawater are different from that of mineral oil, some problems can occur, for instance, poor lubrication, more leakage, and more corrosion. The paper aims to demonstrate the technical feasibility for the water hydraulic vane pump.Design/methodology/approachThe material combinations were selected based on related research in literature. The volumetric efficiency and suction performance were measured in the current experiment. The relations between gap clearances and leakage flow, the contact and the friction forces between a vane tip and a cam contour were simulated based on mathematic models.FindingsThe soft‐hard material combinations in the prototype pump show preferable friction characteristics during tests. The axial clearances are the main channels of leakage flow. Pin type vane pump can reduce the contact force of the vane tip.Originality/valueThis paper outlines some key problems of the water hydraulic vane pump, such as the friction pair material,the structure, and the contact force of the vane tip by means of testing the basic performance of pump and mathematic model.

Reduction of Friction Torque in Vane Pumps by Using Physical Vapour Deposition-Coated Vane

This paper presents a method of reducing friction torque in a hydraulic vane pump through a short-period pump operation by using physical vapour deposition (PVD)-coated vanes. It is well known that the friction torque in a vane pump as well as in other hydraulic machines can be reduced by running-in through a long-time pump operation. This paper revealed that the reduction in the friction torque was derived from lowered friction between a cam contour and vane tips owing to the smoothed surface of a cam contour. Commonly, it was difficult to obtain such an effect through a short-period pump operation. The author has attempted to lessen the surface roughness of the cam contour and to decrease the friction torque of a vane in a short period of time by using vanes coated with an extremely hard PVD layer on their tips. In this study, three kinds of coatings of chromium nitride (CrN), titanium carbonitride (TiCN), and diamond-like carbon (DLC) by PVD were examined. It was found that the TiCN-coated vane was excellent in smoothing the surface roughness of the cam contour and in reducing the friction torque of the vane in a short period of time. It was also shown that the reduced friction torque of the vane depended essentially on the smoothness of the cam contour surface. In addition, the difference of the friction at the vane tip between an ordinary vane and coated vanes was indistinct for the same surface roughness of the cam contour below 0.8 μ m Rz.

A Comparison of the Performance of Environmentally Friendly Anhydrous Fire Resistant Hydraulic Fluids

Abstract Many industries benefit from using fire resistant hydraulic fluids including aviation, steel processing, aluminum die-casting, marine, mining, and many more. In recent years, environmental performance has become an increasingly important feature of hydraulic fluids notably in Europe with the introduction of the European Eco-Label and in the United States with the recommendations provided by the 2002 U.S. Farm Bill for procurement of bio-based materials by Federal agencies. Environmental performance favors esters and vegetable oils as the preferred technologies today but polyalkylene glycols (PAGs) offer an alternative option although they are not derived from renewable sources. The performance of several environmentally friendly fire resistant anhydrous hydraulic fluids based on these technologies has been evaluated in laboratory bench tests. All fluids exhibit excellent hydraulic vane pump wear performance. In high temperature oxidation studies, synthetic products based on esters and PAGs, out-perform vegetable oils. Hydrolytic stability results show hydrolysis of synthetic esters and vegetable oils occurs to form acids in contrast to a PAG formulation, which is more stable. Furthermore the unique water solubility and non-sheening aspects of the PAG product indicate it may be a more favorable choice for use in applications where fluid leakage into water-ways is a concern. By understanding the performance of each product technology, direction can be provided in the type of equipment and industries where these fluids can be used and a discussion pertaining to this is presented herein.

Flow Analysis and Optimization of Port-plate Centrifugal Pump in Electric Motor Pump

Based on the principle of centrifugal pump and the idea of compact design, an electric-motor-pump is developed. It is integrated by an electric motor, a hydraulic vane pump and a port-plate centrifugal pump as a compact hydraulic power unit. The vane pump is as the main pump of the unit. The port-plate centrifugal pump is designed specially for the main pump to improve the suction performance of the electric-motor-pump. The integrated pump demonstrates some attractive advantages such as more compact structure, lower noise, higher efficiency and no external leakage. By computational fluid dynamics (CFD) method, the effects of the main structural parameters of the port-plate centrifugal pump on its outlet pressure and the efficiency are investigated. The design rules for the port-plate centrifugal pump are concluded. The simulation results show that the port-plate centrifugal pump can raise the inlet pressure of the main pump obviously. When the slope angle of the eccentric tube is 45° and the bias angle is between 45°~60°, the maximum power consumption is only about 0.41% of the electric-motor-pump, which also shows that the port-plate centrifugal pump almost do not influences the whole power characteristics of the electric-motor-pump. Its efficiency can be above 95 percent, and the whole efficiency of the centrifugal pump including the outlet channel is 22%. Power loss occurs due to eddy flow from the outlet of the centrifugal pump to the outlet channel to the main pump.

The Lubrication characteristics of the vane tip under pressure boundary condition of oil hydraulic vane pump

The Lubrication Mode of line contacts between the vane and the camring in an oil hydraulic vane pump has been investigated. First, the variations of the radial force of a vane were calculated from previous measurements of dynamic internal pressure in four chambers surrounding a vane. Next, the lubrication modes were distinguished with Hooke’s chart, which is an improvement over Johnson’s chart. Finally, the influence of the boundary conditions in the lubrication region on the fluid film lubrication was examined by calculating the film pressure distributions. The results showed that the lubrication mode of the vane tip exists in the rigidvariable-viscosity region, and that discharge pressure higher than 7 MPa greatly affects the oil film pressure in the small and the large arc section because of the Piezo-viscous effect.