A novel hydraulic pulsation reduction component based on discharge and suction self-oscillation: Principle, design and experiment

The reduction of fluid ripple in pipes is extremely important for the reliability and safety of aircrafts and ships. Currently, most researches only pay attention to the discharge port and ignore the suction port and the inherent characteristic of the axial pump between both ports, which may cause significant underestimation of fluid ripple especially in the closed-loop hydraulic system. Therefore, the aim of this study is to propose a novel passive fluid ripple attenuator, which can simultaneously reduce discharge and suction pulsation of the axial-piston pump, and adapt to the condition of frequent change of load reversing in closed hydraulic system. First, the phase matching rule is discovered between discharge and suction ripple, and then based on that, the proposed discharge and suction self-oscillation principle is verified through simulation on the phase relationship of the pump internal pistons, instead of considering the two separately as before. The attenuator designed with the concept of the discharge and suction self-oscillation principle is presented, and models of how ripple generates and the attenuator works are represented analytically. The corresponding simulation model is established, and the result indicates that the ripple of both ports of the piston pump is weakened significantly. Moreover, one testing platform is developed, and the experimental study is conducted on the discharge and suction ripple. It proves that the proposed attenuator based on discharge and suction self-oscillation principle can reduce the fluid ripple effectively.

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The Efficiency of Mobile Hydraulic System with Diesel Engine and Axial Piston Pump Analysis

Journal of Engineering Research ◽

10.36909/jer.11137 ◽

2021 ◽

Vol 9 ◽

Author(s):

Murat Kapsiz ◽

Keyword(s):

Diesel Engine ◽

Fuel Consumption ◽

Power Unit ◽

Hydraulic System ◽

Co2 Emission ◽

Power Loss ◽

Piston Pump ◽

Hydraulic Systems ◽

Axial Piston Pump ◽

Axial Piston

Hydraulic systems are used in a wide variety of applications, stationary as well as mobile. Hydraulic pumps und motors are in many cases used for both propulsion and various work functions and is thus often a significant user of energy. Efficiency performance of a mobile hydraulic systems over a wide range of pressure and speed conditions is crucially important for power unit to save energy. In this study, efficiency of a mobile hydraulic system are studied. Mobile hydraulic system is equipped with diesel engine as power unit and axial piston pumps used for hydraulic power. The relationships between the efficiency of the axial piston pump and the power loss, the efficiency of diesel engine and the output power were explained by graphics. The average power loss of axial piston pump have changed from 0.1 kW to 2.5 kW. Losses of an axial piston pump have been determined thus fuel consumption and CO2 emission caused by these losses were shown by graph. The CO2 emission affected by the increase in pressure and speed, it reached from 5.231 kg/h to 5.61 kg/h. The research focused on analysis for axial piston pump in mobile applications, with emphasis on pump losses, fuel consumption and CO2 emission.

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Development of an asymmetric axial piston pump for displacement-controlled system

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406213508385 ◽

2013 ◽

Vol 228 (8) ◽

pp. 1418-1430 ◽

Cited By ~ 18

Author(s):

Jiahai Huang ◽

Hu Zhao ◽

Long Quan ◽

Xiaogang Zhang

Keyword(s):

Hydraulic System ◽

Cost Effective ◽

Difficult Problem ◽

Valve Plate ◽

Piston Pump ◽

Flow Rate Ratio ◽

Axial Piston Pump ◽

Controlled System ◽

Delivery Pressure ◽

Axial Piston

Pump-controlled systems can eliminate throttling losses and improve the work efficiency of mobile hydraulic system. But one difficult problem for that is the differential volumetric flow through a single rod cylinder which is widely used in mobile hydraulic system. Several solutions have been presented to deal with it so far, but there still has not been a cost-effective solution to it. In recent years, an asymmetric pump-controlled asymmetric cylinder strategy has been presented to deal with this problem. In order to achieve this goal, an asymmetric axial piston pump with three ports was developed in this research. The flow rate ratio of the three ports of asymmetric axial piston pump was designed as 1: γ:(1 − γ), in which γ was the area ratio of a single rod cylinder. An important task in the development of asymmetric axial piston pump was the design of the valve plate. There were three intake/discharge slots (slots A, B, and T) in the valve plate. The pumping dynamics of a fixed displacement asymmetric axial piston pump were investigated using software package ITI-SimulationX® and the performances of its prototype were tested. Simulation and experimental results show that with careful design, a V-shaped cross-section groove at the leading side of slot T can effectively improve the performance of asymmetric axial piston pump, and delivery pressure performance of port B is better than that of port T. Therefore, port T should be linked with low-pressure sources such as accumulator, and port B can be connected to high pressure sources. This work lays a theoretical foundation for a new exploration to pump-controlled system.

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Analyses of the Long-Term Performance and Tribological Behavior of an Axial Piston Pump Using Diamondlike-Carbon-Coated Piston Shoes and Biodegradable Oil

Journal of Tribology ◽

10.1115/1.2805442 ◽

2007 ◽

Vol 130 (1) ◽

Cited By ~ 13

Author(s):

M. Kalin ◽

F. Majdič ◽

J. Vižintin ◽

J. Pezdirnik ◽

I. Velkavrh

Keyword(s):

Hydraulic System ◽

Performance Enhancement ◽

Test System ◽

Piston Pump ◽

Axial Piston Pump ◽

Hydraulic Test ◽

Actual Application ◽

Diamondlike Carbon ◽

Axial Piston

This work reports on the performance enhancement of a real-scale hydraulic system consisting of diamondlike-carbon (DLC)-coated components in combination with biodegradable oil in long-term experiments under conditions simulating those in an actual application. The performance of a hydraulic axial piston pump with DLC-coated piston shoes was evaluated in a newly designed, dedicated hydraulic test system using fully formulated biodegradable, synthetic ester oil. For comparison, an equal but separated hydraulic system with a conventional commercial pump and stainless-steel shoe surfaces was tested. The tests were run at 85% of the maximum pump load and an oil temperature of around 80°C for a period of 2000h, which corresponds to more than 1yr of continuous 8h∕day operation in an application. A major abrupt oxidation-induced degradation of the oil did not occur in either system; however, the oil from the system comprising the DLC-coated shoes showed noticeably and consistently better results. The wear of the DLC-coated shoes, especially during the running in, was much lower than that in the conventional steel system. Only minor polishing wear was observed on the DLC shoe’s sliding surfaces during the test period, while on the steel shoe’s surfaces, many scratches were found and some erosion of the edges was detected.

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Leakage Based Condition Monitoring and Pressure Control of the Swashplate Axial Piston Pump

Volume 2: Combustion, Fuels, and Emissions; Renewable Energy: Solar and Wind; Inlets and Exhausts; Emerging Technologies: Hybrid Electric Propulsion and Alternate Power Generation; GT Operation and Maintenance; Materials and Manufacturing (Including Coatings, Composites, CMCs, Additive Manufacturing); Analytics and Digital Solutions for Gas Turbines/Rotating Machinery ◽

10.1115/gtindia2019-2385 ◽

2019 ◽

Author(s):

Neeraj Kumar ◽

Bikash Kumar Sarkar ◽

Subhendu Maity

Keyword(s):

Hydraulic System ◽

Pressure Control ◽

Piston Pump ◽

Chamber Pressure ◽

Leakage Flow ◽

Axial Piston Pump ◽

Highly Nonlinear ◽

Displacement Pump ◽

Variable Displacement ◽

Axial Piston

Abstract This research mainly focused on the axial piston variable displacement pump, which is the most important part of the fluid power system. The variable displacement axial piston has been found as versatile and flexible for electro-hydraulic applications. Heavy industries such as automobile, aircraft, and mining use an axial piston pump due to its high power to weight ratio, continuous variable power transmission, low inertia, self-lubricating properties, and good controllability. The main challenges with the hydraulic system are highly nonlinear, leakages, unknown external disturbance, etc. The mathematical model of the variable displacement pump along with swashplate control has been developed. The model is used to identify the pump health condition with pressure and flow measurement, i.e., ripple pattern. The pressure and flow ripple will vary from the regular pattern due to wear and tear, i.e., increased leakage flow. The main source of the increase in leakage flow is due to wear in piston and cylinder bore. The piston chamber pressure, kinematical flow, and discharge area model of the pump has been validated with the existing results. The pump pressure control is very much essential for the enhancement of the performance of the electro-hydraulic system. In the present study, a conventional PID controller has been used as a backup to maintain system performance within the permissible faults. The electro-hydraulic system has been employed for swash-plate control of the pump to obtain desire pressure flow at the exit of the pump. MATLAB Simulink has been used for the simulation study of the pump.

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Aircraft hydraulic axial piston pump fundamental pulsation and simulation

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1208/1/012008 ◽

2021 ◽

Vol 1208 (1) ◽

pp. 012008

Author(s):

Želimir Husnić ◽

Remzo Dedić ◽

Faris Ustamujić ◽

Zlata Jelačić

Keyword(s):

Fundamental Frequency ◽

Health Monitoring ◽

Hydraulic System ◽

Pressure Pulsation ◽

Piston Pump ◽

Axial Piston Pump ◽

System Health Monitoring ◽

Predictive Approach ◽

Hydraulic Axial Piston Pump ◽

Axial Piston

Abstract The axial piston pump for aircraft hydraulics systems and other high pressure hydraulic system applications is presented. This paper discusses the pump’s pressure pulsation and the fundamental frequency. Pressure pulsation associated with single piston failure is explained in relation to its fundamental frequency. A predictive approach in maintenance and pump sub system health monitoring is proposed, using numerical modelling and applicable software.

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