Wyniki wyszukiwania - BazTech

1

Wpływ struktury sterowania oraz lepkości oleju na straty tarcia w siłowniku

Skorek G.

Przegląd Mechaniczny

|

2018

|

nr 6

32--38

PL

Problematyka badań energetycznych układów hydraulicznych z siłownikami, pozornie prostymi maszynami wyporowymi, okazuje się bardziej złożona niż w przypadku układów z silnikiem hydraulicznym obrotowym. Przedstawione w artykule badania umożliwiają poznanie wpływu obciążeń zewnętrznych, wymaganej prędkości, struktury układu zasilającego, lepkości oleju hydraulicznego na straty tarcia, a więc na sprawność napędu siłownikowego.

EN

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 losses, and the efficiency of cylinder drive.

2

Study of losses and energy efficiency of hydrostatic drives with hydraulic cylinder

Skorek G.

Polish Maritime Research

|

2018

|

nr 4

114--129

EN

Energy efficiency of hydrostatic transmissions, and especially efficiencies of drives with motor speed controlled by throttle, as well as efficiency of hydraulic servomechanisms can in fact be higher than the efficiency values most frequently given by the respective literature in this field. With the progress achieved in recent years in the development of hydraulic systems it is becoming necessary to develop methods for precise energy efficiency calculation of such systems. It is difficult to imagine that more and more, better and better machines and control elements could be used without the possibility of a mathematical tool at our disposal to enable an accurate analysis and assessment of behavior of the system in which such machines and control elements have been applied. The paper discusses energy savings using mathematical model of losses in elements, the energy efficiency of the system. 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 pump-driven hydraulic cylinder. The article shows the impact on the output (useful) power consumed in the considered systems, and the impact on the power consumed of the loss power in the individual elements. The paper presents also formulas of loss power, formulas of energy efficiency connected with investigated hydrostatic drives, two schematic diagrams of hydraulic systems, their principle of operation and problems of studying losses in elements and energy efficiency characteristics of systems consisting of a feed assembly, control set and cylinder. 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 speed and load of a cylinder, which were different due to structure and ability of energy saving, were presented and compared.

3

Energy saving systems of hydrostatic drives for ship deck machines

Skorek G.

New Trends in Production Engineering

|

2018

|

Vol. 1, Iss. 1

507--514

EN

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). Energy savings in a constant capacity pump operation can be achieved by means of overflow valve controlled by the oil outlet pressure between the directional throttling control valve and the cylinder. Although structural volumetric losses cannot be eliminated in such a system, but it is possible to reduce considerably structural pressure losses, mechanical losses and volumetric losses in the pump, and mechanical losses in the cylinder too. The paper discusses these energy savings using an earlier developed by Paszota mathematical model of losses in elements, the energy efficiency of the system and the operating range of the cylinder. The paper also presents a comparison of the energy behavior of two widespread structures of hydrostatic systems: a standard individual systems with a throttling steering fed by a constant capacity pump. Both system 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 and ability of energy saving, were presented and compared.

4

Influence the applied control structure on energy efficiency of the hydrostatic system

Skorek G.

Journal of KONES

|

2018

|

Vol. 25, No. 3

411--418

EN

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.

5

Friction losses in a linear hydraulic motor as a result of the influence of the control structure and oil viscosity

Skorek G.

Journal of KONES

|

2018

|

Vol. 25, No. 4

377--384

EN

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.

6

Charakterystyki mocy strat energetycznych w wybranych elementach układów hydraulicznych

Skorek G.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2017

|

nr 100

164--178

PL

W artykule porównano dwa układy ze sterowaniem dławieniowym, które zasilane były pompą o stałej wydajności. Poruszono tematykę związaną ze stratami energetycznymi układów hydrostatycznych z silnikami hydraulicznymi liniowymi sterowanymi proporcjonalnie rozdzielaczem proporcjonalnym. Przedstawiono i porównano wykresy mocy strat dwóch układów hydraulicznych pracujących przy tych samych parametrach prędkości i obciążenia siłownika, lecz różniących się strukturą oraz możliwością oszczędności energii.

EN

In this article two hydrostatic systems with a throttling steering fed by a constant capacity pump were compared. The subject matter connected with an energy losses of hydrostatic systems with hydraulic linear motors controlled by proportional directional valve was presented. Diagrams of power losses of two hydraulic systems worked at the same parameters of a speed and a load of hydraulic linear motor, which were different due to structure and ability of an energy saving, were presented and were compared.

7

Verification the mathematical model of energy efficiency of hydraulic system

Skorek G.

Journal of KONES

|

2017

|

Vol. 24, No. 3

275--281

EN

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.

8

Characteristics of loss power in compared hydraulic systems

Skorek G.

Journal of KONES

|

2017

|

Vol. 24, No. 2

217--223

EN

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.

9

Wpływ lepkości oleju na charakterystyki wybranych elementów układów hydraulicznych o sterowaniu proporcjonalnym siłownika

Skorek G.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2016

|

nr 96

143--165

PL

W artykule przedstawiono wpływ lepkości oleju na charakterystyki wybranych elementów układów hydraulicznych. Zakres niskich temperatur oleju jest niedopuszczalny głównie z powodu złych warunków zasysania pompy i zjawiska kawitacji, a w razie całkowitego przerwania strumienia na ssaniu pompy – z powodu możliwości zatarcia pompy na skutek braku smarowania. Zakres wysokich temperatur nie nadaje się do pracy nie tylko z powodu nadmiernego spadku lepkości i związanego z tym wzrostu przecieków, lecz także ze względu na przyspieszony rozkład oleju. W elementach układu hydraulicznego występują straty energetyczne, które są między innymi funkcją lepkości zastosowanej cieczy roboczej, a także straty energetyczne, które praktycznie nie zależą od lepkości. W artykule przedstawiono również zakres zmiany lepkości kinematycznej oleju hydraulicznego wykorzystywanego jako medium na stanowisku badawczym, opis schematu badanych układów hydraulicznych o sterowaniu proporcjonalnym siłownika oraz charakterystyki dotyczące wybranych elementów będące wynikiem badań i niezbędne do określenia współczynników strat występujących w układach.

EN

The article presents the effect of oil viscosity on the characteristics of the components selected hydraulic systems. Range is inadmissible low temperatures mainly due to bad suction pump cavitation and, in the event of total interruption of flow on the suction side of the pump – due to seizing of the pump due to lack of lubrication. Furthermore, the high temperature is not suitable for use not only because of an excessive drop in viscosity and associated increase in leakage, but also for accelerated decomposition of oil.The elements are hydraulic energy losses which are, inter alia, a function of the viscosity of the working fluid used and the energy losses which practically depends on the viscosity. The article presents the range of changes in the kinematic viscosity of the hydraulic oil used as a medium on the test bench, description, schematics studied hydraulic systems of proportional control actuator and the characteristics for the selected items as a result of research and necessary for the determination of the losses occurring in the systems.

10

Hydropneumatyczne zawieszenie w samochodach osobowych – zasada działania

Skorek G.

Napędy i Sterowanie

|

2016

|

R. 18, nr 11

86--97

PL

Artykuł objaśnia zasadę działania zawieszenia hydropneumatycznego stosowanego od lat w samochodach osobowych francuskiej marki Citroën, zapewniającego wyższy komfort jazdy niż zawieszenie aut z konwencjonalnym rozwiązaniem resorowania. Układ hydrauliczny jest w tym przypadku centralnym układem otwartym, którego zadaniem jest: wypoziomowanie nadwozia oraz utrzymywanie go na odpowiednim poziomie niezależnie od obciążenia, umożliwienie regulacji wysokości w określonym zakresie oraz zasilanie układu hamulcowego i wspomagania układu kierowniczego. W artykule ograniczono się do omówienia zasady działania konwencjonalnego hydraulicznego układu podnoszenia stosowanego w starszych modelach oraz przedstawiono budowę wybranych elementów układu hydropneumatycznego. Wspomniano także o nowych generacjach zawieszenia Hydroactive, które w kolejnych latach stosowano w coraz nowszych modelach marki Citroën.

EN

Article explains the principle of hydropneumatic suspension used for years in passenger cars French brand Citroën, providing greater comfort than the suspension of cars with conventional suspension solution. The hydraulic system is in this case an open central control unit whose function is the leveling of the body and maintain it at the proper level regardless of the load, allowing height adjustment in a certain range and the power brake and power steering. This article is limited to arrange the principles of conventional hydraulic lifting system used in older models and presents the construction of selected elements of the hydropneumatic. Also mentioned the new generations of Hydractive suspension, which in subsequent years been used in more recent models Citroën.

11

Tests constant capacity pump considering the effect of viscosity and compressibility aerated oil

Skorek G.

Journal of KONES

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2016

|

Vol. 23, No. 1

305--312

EN

The paper presents mathematical models of the losses occurring in the pump with a theoretical capacity per revolution of the shaft and geometric (variable) performance on the rotation of the shaft. These models were used to laboratory testing and simulation energy losses in the pump to judge the energy efficiency of the pump and the efficiency of the hydrostatic drive. The results of research and analyses should be able to create and exploit the possibilities simulation programs support the process of designing hydraulic systems. Pursuing such programs will allow fast determination of the efficiency of the hydrostatic transmission with a positive displacement pump, composed of any item at any point of the fieldwork. These programs enable the selection of optimal in terms of energy, the operating parameters of the system. In an era of increasingly expensive energy, even a small reduction of losses can bring tangible economic benefits during machine operation. It is important to know the energy efficiency of the transmission, under not only nominal conditions, but also changes in the whole range of working conditions: the speed and load of the hydraulic motor, the viscosity of hydraulic oil particularly in the parameters or the longest occurring during operation. It is necessary, therefore, to design stage gear on a detailed analysis of energy enabling optimal selection of components and operating parameters of the system.

12

Comparison of the structural and total energy efficiency of selected hydraulic systems with proportional control linear motor

Skorek G.

Journal of KONES

|

2016

|

Vol. 23, No. 2

317--324

EN

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.

13

Nowatorska metoda badania strat ciśnieniowych w pompie wyporowej

Skorek G.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2014

|

nr 83

222--231

PL

Artykuł przedstawia nowatorską metodę badania strat ciśnieniowych w pompie o zmiennej wydajności. Określenia strat ciśnienia w kanałach i rozdzielaczu pompy można dokonać na dwa sposoby. Przy pierwszym sposobie opory przepływu muszą być mierzone w pompie z wymontowanymi nurnikami. Wtedy to przez kanały pompy tłoczona jest ciecz o natężeniu zmiennym od wartości bliskiej zeru do wartości maksymalnej. Badanie pompy wykonywane jest przy stałej prędkości obrotowej. W przypadku, kiedy demontaż nurników jest niemożliwy lub po ich demontażu, napęd wałka pompy nie wprawia wirnika w ruch obrotowy, stanowisko takie nie może być zastosowane. Nowa metoda badania strat ciśnieniowych w pompie wyporowej opiera się na zjawisku kawitacji, która powstaje w komorze roboczej pompy w trakcie jej połączenia z przewodem dopływowym. W artykule zaprezentowano również schematy stanowisk, zakres pomiarów, otrzymane wykresy oraz przeprowadzono ich wnikliwą analizę. Zaproponowano też sposób pomiaru strat w pompach o stałej wydajności, a także wspomniano o pomiarze strat ciśnieniowych w silnikach hydraulicznych. W pracy nawiązano do modelu zachowania energetycznego pomp wyporowych zaproponowanego przez Z. Paszotę.

EN

This article presents a novel method to study pressure losses in the pump with variable displacement. Determination of pressure loss in ducts and distributor pumps can be done in two ways. With the first method, the flow resistance must be measured in the pump plungers with a dismounted. Then the pump through the inside of the oil is pumped from the variable intensity almost zero to a maximum value. The test pump is performed at a constant speed. In the case where removal is impossible or plungers, the dismantling, the drive shaft of the pump sets is not rotor rotation, such a position can not be applied. The new test method loss of pressure in the pump displacement is based on the phenomenon of cavitation, which is formed in the working chamber of the pump while it is connected to the inlet line. This article also includes diagrams positions, the range of measurements obtained graphs and conducted their rigorous analysis. Proposed a method for measuring the loss of fixed speed pumps, and also mentioned the measurement of pressure losses in the hydraulic motors. The paper refers to the behavior model of the energy of positive displacement pumps proposed by Z. Paszota.

14

The opportunities for getting energy savings in the hydrostatic drive system

Skorek G.

Journal of KONES

|

2014

|

Vol. 21, No. 2

273--280

EN

Full picture of the energy losses in a hydrostatic drive system is a picture of the power of energy losses in the system elements. Paper presents the areas of the power fields of energy losses occurring in the elements of some hydraulic systems with different structures of the hydraulic motor speed control. Proposed graphical interpretation allows analysing and comparing different hydrostatic drive systems. In many constructed and manufactured machines currently used hydrostatic drive systems or electro hydrostatic systems of varying complexity. Today, the need for energy-efficient systems forces to some extent the development and improvement of computational methods using computer aided relating to energy efficiency systems. Hydrostatic systems especially in modern machines play a very important role. Actuators, such as hydraulic motors, hydraulic cylinders is commonly used for a long time, including on machines and equipment land and marine. Unawareness of proportions of the energy, volumetric, pressure and mechanical losses in elements is often the case. Problems connected with energy efficiency are essential for improvement of functionality and quality of hydrostatic drive systems, characterised by unquestioned advantages. Energy efficiency of hydrostatic transmissions, particularly those with throttling control of the motor speed, and also efficiency of the hydraulic servomechanism systems may be in fact higher than the values most often quoted in publications on the subject.

15

Układy hydrostatyczne ze sterowaniem dławieniowym

Skorek G.

Hydraulika i Pneumatyka

|

2014

|

nr 5

16--21

16

Ryzykowne rozwiązania instalacji sanitarnych i grzewczych w polskim wielorodzinnym budownictwie mieszkaniowym

Skorek G.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

|

2014

|

T. 45, nr 6

226--228

PL

Tradycyjnym materiałem wykorzystywanym do budowy instalacji wodnych w budynkach były rury i kształtowniki wykonane z ocynkowanej stali. W ostatnich latach popularne stało się stosowanie do rozprowadzania wody sanitarnej oraz grzewczej rur i łączników z tworzyw sztucznych. Nie jest jeszcze możliwe ustalenie długości czasu bezawaryjnego użytkowania tych instalacji, gdyż są one zbyt krótko stosowane. Ponadto rury te mogą zostać uszkodzone mechanicznie przez przeróbki w czasie użytkowania mieszkań. Instalacja taka powinna być tak zaprojektowana, aby była możliwa łatwa diagnostyka i tania naprawa. Niniejszy artykuł stanowi próbę zwrócenia uwagi na poważne wady oraz konsekwencje zastosowania nieodpowiedniego, tj. trójnikowego rozprowadzania wody sanitarnej i grzewczej w mieszkaniach w przypadku użycia wielowarstwowych rur typu PE-Xc/A1/PE w instalacjach podpodłogowych.

EN

The traditional material used for the construction of water systems in buildings were tubes and profiles made of galvanized steel. In recent years it has become popular to distribute the use of sanitary and heating water pipes and fittings made of plastics. It is not yet possible to determine the length of time of trouble- free use of these facilities, as a relatively very short time they are used. Moreover, these pipes can be damaged mechanically by the processing time of housing. This installation should be designed so that it can be easy and inexpensive repair diagnostics. This article is an attempt to draw attention to the serious flaws and the consequences of using the wrong distribution, ie T- piece sanitary water and heating in homes for the use of multilayer pipes PE-Xc/Al/PE type of underfloor installations.

17

Wybrane sprawności układu ze sterowaniem proporcjonalnym siłownika

Skorek G.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2013

|

nr 81

98--110

PL

Istnieją obszary nierozpoznane, związane z zachowaniem się elementów w układach hydraulicznych o różnych strukturach. Brak często świadomości dotyczącej proporcji strat energetycznych, objęto- ściowych, ciśnieniowych i mechanicznych występujących w elementach. Zagadnienia związane ze sprawnością energetyczną są istotne dla poprawy funkcjonalności i podniesienia jakości hydrostatycznych układów napędowych, charakteryzujących się, obok niewątpliwych zalet, stosunkowo niską sprawnością w porównaniu z innego rodzaju napędami. Sprawność energetyczna przekładni hydrostatycznych zwłaszcza ze sterowaniem dławieniowym prędkości silnika, a także sprawność układów serwomechanizmów hydraulicznych, może być w rzeczywistości wyższa od wartości najczęściej podawanych w literaturze przedmiotu. Możliwość obliczania rzeczywistej sprawności całkowitej układu hydraulicznego jako funkcji wielu parametrów o niej decydujących staje się narzędziem całościowej oceny jakości projektowanego układu. W artykule porównano sprawności układów o sterowaniu proporcjonalnym siłownika ze sprawnością układu o sterowaniu objętościowym pompą o zmiennej wydajności. Pokazano również dwa schematy badanych układów hydrostatycznych, przedstawiono ich zasadę działania oraz problematykę badań strat w elementach i sprawności energetycznej układów składających się z zespołu zasilającego, zespołu sterowania i siłownika.

EN

There are areas unrecognized, concerning the behavior of components in hydraulic systems with different structures. No common awareness of the energy loss ratio, volume, pressure and mechanical occurring in parts. Issues related to energy efficiency are important to improve the functionality and improve the quality hydrostatic drive systems, characterized by, in addition to obvious advantages, the relatively low efficiency in comparison with other types of drives. Energy efficiency hydrostatic especially throttling control engine speed and efficiency of the hydraulic servo systems may actually be higher than that of the most frequently used in the literature. The possibility of calculating the overall efficiency of the hydraulic system as a function of various parameters of it becomes a tool for determining the overall assessment of the quality of the proposed system. This paper compares the performance of control systems commensurate with the efficiency of the motor by controlling the volume pump with variable displacement. Also shown are the two regimens studied hydrostatic shows the principle of action and research issues of losses in the elements and the energy efficiency of systems consisting of a power supply unit, control unit and actuator.

18

Energy efficiency of a hydrostatic drive with proportional control compared with volumetric control

Skorek G.

Polish Maritime Research

|

2013

|

nr 3

14--19

EN

There are uninvestigated areas connected with behaviour of elements in hydraulic systems with different structures. Unawareness of proportions of the energy, volumetric, pressure and mechanical losses in elements is often the case. Problems connected with energy efficiency are essential for improvement of functionality and quality of hydrostatic drive systems, characterised by unquestioned advantages but also by relatively low efficiency in comparison with other types of drive. Energy efficiency of hydrostatic transmissions, particularly those with throttling control of the motor speed, and also efficiency of the hydraulic servo-mechanism systems may be in fact higher than the values most often quoted in publications on the subject. Possibility of calculating the real value of the hydraulic system overall efficiency as a function of many parameters influencing it, becomes a tool of complete evaluation of the designed system quality. The paper compares efficiencies of systems with cylinder proportional control and efficiency of the system volumetric control by a variable capacity pump. Presented are also two schematic diagrams of the investigated hydrostatic systems, their principle of operation and problems of studying losses in elements and energy efficiency of systems consisting of a feed assembly, control set and cylinder.

19

Sprawność energetyczna napędu hydrostatycznego

Skorek G.

Hydraulika i Pneumatyka

|

2013

|

nr 6

7--10

20

Porównanie dwóch układów hydrostatycznych ze sterowaniem dławieniowym - zasada działania, rozkład ciśnień oraz straty mocy

Skorek G.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2011

|

nr 71

115-130

PL

W artykule porównano dwa układy ze sterowaniem dławieniowym, zasilane pompą o stałej wydajności. Przedstawiono również rozkład ciśnień w układach oraz formę graficzną, ilustrującą moce i straty mocy w poszczególnych elementach. Porównano zarówno wielkość mocy poszczególnych strat, wynikających z zastosowanej struktury sterowania prędkości silnika hydraulicznego liniowego, jak i moc pobieraną przez pompę od napędzającego ją silnika elektrycznego, konieczną do zapewnienia wymaganej niezmienionej wielkości użytecznej, napędzanego pompą, silnika hydraulicznego liniowego. Układ hydrauliczny napędu i sterowania proporcjonalnego silnika hydraulicznego liniowego może być zasilany pompą o stałej wydajności, współpracującą z zaworem przelewowym, stabilizującym ciśnienie zasilania rozdzielacza proporcjonalnego na poziomie ciśnienia nominalnego, bądź pompą współpracującą z zaworem przelewowym sterowanym ciśnieniem na dopływie do odbiornika. Układ zmiennociśnieniowy umożliwia obniżenie strat w pompie, w zespole sterowania i w silniku hydraulicznym liniowym.

EN

This publication compares two hydrostatic systems with a throttling steering fed by a constant capacity pump. It also presents a distribution of pressures in hydraulic units as well as a graphic form, which illustrates powers and losses of power in particular elements. The analysis allows to compare the values of power of losses ensuing from the used structure of control of the hydraulic linear motor speed as well as the value of power absorbed by the pump from its driving electric motor, power necessary for providing the required stable value of useful power of the hydraulic linear motor driven by the pump. A system of drive and proportional steering of hydraulic linear motor can be fed by constant capacity pump cooperated with an overflow valve, which stabilizes a supply pressure of proportional valve on a level of nominal pressure, or by pump cooperated with controlled overflow valve a pressure on inlet to receiver. A variable pressure system enables the losses decreasing in the pump, in the control unit and in the hydraulic linear motor.