Temat: hydraulic losses - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Verification the mathematical model of energy efficiency of hydraulic system
Autorzy:: Skorek, G.
Powiązania:: https://bibliotekanauki.pl/articles/245887.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: hydraulic systems
hydraulic transmission
energy efficiency
constant capacity pump
energy losses
mathematical model
Opis:: The article presents the laboratory verification of the mathematical description of losses and energy efficiency of the hydraulic transmission with proportionally controlled cylinder supplied by the constant capacity pump in the system of constant pressure is presented. The axial piston pump with pivoting rotor supplied to the system consisted of proportional directional control valve and linear motor – hydraulic cylinder at constant pressure, cooperating with an overflow valve. The choice of the analysed system is not accidental. There is always a view in literature about the very limited energy capabilities of a proportional control system. For this purpose, measurement methods were developed and a test stand was adapted. It consists of two systems: tested and loading. Measurements during the tests were recorded up to date on the computer hard disk. In order to allow for comparison of the total efficiency of the system with the efficiency derived from the simulation, the ki coefficients determining the energy losses of the individual components were calculated. Investigations have shown a high convergence mathematical description of energy losses in the elements of the system efficiency and reality. This allows accurate simulation determining the energy efficiency of the field at every point in its operation, i.e. at any speed and any load-controlled hydraulic cylinder. The speed and load range of the hydraulic cylinder can also be accurately simulated.
Źródło:: Journal of KONES; 2017, 24, 3; 275-281
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Characteristics of loss power in compared hydraulic systems
Autorzy:: Skorek, G.
Powiązania:: https://bibliotekanauki.pl/articles/241595.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: power
energy losses
hydraulic system
pump
throttling valve
cylinder
Opis:: In this article, two hydrostatic systems with a throttling steering fed by a constant capacity pump were compared. It also includes a subject matter connected with an energy loss power of hydrostatic systems with hydraulic cylinder controlled by proportional directional control valve. Diagrams of loss power of two hydraulic systems worked at the same parameters of a speed and a load of hydraulic cylinder, which were different due to structure and ability of an energy saving, were presented and were compared. There are possibilities to reduce energy losses in proportional control systems (in the pump, in the throttle control unit, especially in the cylinder), and thus to improve the energy efficiency of the throttling manifold. The considerations allow for comparison of the loss power resulting from the applied hydraulic control structure of the hydraulic cylinder and the power consumed by the pump from the electric motor that drives it, the power necessary to provide the required unchanged usable pump-driven hydraulic cylinder. Presents the impact on the output (useful) power of the power consumed in the considered systems, and the impact on the power consumed of the loss power in the individual elements. Instantaneous useful power of the cylinder, which is determined by the product of force and speed of the cylinder rod, is independent of all losses. There are mechanical loss power occurs in the cylinder, the loss power in the conduits, the structural volume and pressure loss power that are associated with the throttling control and loss power in the pump: pressure, volumetric and mechanical which have to be added to the useful power. As a result, the sum of the effective useful power and the loss power of all system is the instantaneous value of the power consumed by the pump from the electric motor that drives it.
Źródło:: Journal of KONES; 2017, 24, 2; 217-223
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Friction losses in a linear hydraulic motor as a result of the influence of the control structure and oil viscosity
Autorzy:: Skorek, G.
Powiązania:: https://bibliotekanauki.pl/articles/241950.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: friction force
mechanical losses
energy efficiency
oil viscosity
hydrostatic drive
hydraulic cylinder
Opis:: The problem of energy tests of hydraulic systems with hydraulic cylinders, seemingly simple displacement machines, is more complex than that of rotary hydraulic systems. The results of the researches provide an insight into the impact of external loads, required speed, structure of the power supply system, viscosity of hydraulic oil on friction loss, and the efficiency of cylinder drive. The hydraulic cylinder is the strongest structure in the system. Failure of the system is most likely due to failure of the pump supplying the cylinder. The high load of the pump is often caused by the very low energy efficiency of the cylinder, which, despite a relatively low external load, requires high inlet pressure due to large mechanical losses of friction between the piston and the cylinder and between the piston rod and gland. These losses depend on the type of seal used, its shape, the material it is made from, pre-clamp, and the operating parameters of the cylinder. Improperly sealed or assembled seals can cause energy losses of up to 25%. Due to the use of moving seals in the hydraulic cylinder, its energy behaviour is completely different compared to the energy behaviour of a rotary motor, which does not have any seals. The friction force connected with the work of the sealing joints and the mechanical efficiency of the cylinder are determined not only by the external load but also by the method of the applicable supply of the cylinder resulting from the throttling structure, and in particular the pressure level generated in the discharge chamber of the cylinder.
Źródło:: Journal of KONES; 2018, 25, 4; 377-384
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Comparison of the structural and total energy efficiency of selected hydraulic systems with proportional control linear motor
Autorzy:: Skorek, G.
Powiązania:: https://bibliotekanauki.pl/articles/247433.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: energy efficiency
power of losses
hydrostatic system
throttling steering
pump
hydraulic linear motor
proportional directional valve
Opis:: In the paper are presented the diagrams of the structural energy efficiency of system with the throttling control assembly and total energy efficiency of the system with constant or variable capacity pump cooperating an overflow valve with the throttling control of the linear hydraulic motor. Diagrams of total energy efficiency of three hydraulic systems working at the same parameters of speed and load of hydraulic linear motor, which were different due to structure and ability of energy saving were presented and compared. This publication also presents analyses and compares the areas of the power fields of energy losses occurring in the elements of three compared hydraulic systems with different structures of the hydraulic linear motor speed control on example on Load Sensing system. The graphical interpretation of the power of losses in the hydrostatic drive and control system elements lets to compare the same power fields of energy losses with other power fields of another structure. This enables to understand what energy losses are the biggest and in which elements of compared hydraulic systems. The best possibility to use in system, as a supply source of the hydraulic cylinder speed series throttling control assembly, is a set consisting of a variable capacity pump cooperating with a Load Sensing (LS) regulator, which totally eliminates the structural volumetric losses in a system. Power ΔPstv of structural volumetric losses is equal to zero, because the current pump capacity QP is adjusted, by the LS regulator, to the current flow intensity QM set by the throttling assembly.
Źródło:: Journal of KONES; 2016, 23, 2; 317-324
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Influence the applied control structure on energy efficiency of the hydrostatic system
Autorzy:: Skorek, G.
Powiązania:: https://bibliotekanauki.pl/articles/245430.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: energy efficiency
power of losses
hydrostatic system
throttling steering
pump
hydraulic linear motor
proportional directional valve
deck machinery
Opis:: A control system with a proportional directional throttling control valve or a directional control servo valve, controlling a cylinder (linear hydraulic motor) is used in the ship steering gear drive, in the controllable pitch propeller control, in the variable capacity pump control system for hydraulic deck equipment motors or fixed pitch propellers in small ships (for example ferries). The hydraulic system is designed first of all taking into consideration the nominal parameters of the cylinder load and speed. For such parameters, the energy efficiency of the elements and complete system is described. Meanwhile the exploitation conditions can vary in full range changes of the cylinder load and speed coefficients. The article presents a comparison of the energy behaviour of two widespread structures of hydrostatic systems: a standard individual systems with a throttling steering fed by a constant capacity pump. Both hydraulic solutions are described and equations of the total efficiency η of the system are presented. Diagrams of energy efficiency of two hydraulic systems working at the same parameters of a speed and a load of hydraulic linear motor, which were different due to structure are presented and compared, as well ability of energy saving. This publication also presents analyses and compares the areas of the power fields of energy losses occurring in the elements of two hydraulic systems with different structures of the hydraulic linear motor speed control.
Źródło:: Journal of KONES; 2018, 25, 3; 411-418
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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