Wyniki wyszukiwania - Biblioteka Nauki

1

Vegetable oils derivatives as the modifiers of the lubricating properties of water

100%

Sułek M. , Sas W. , Przondo J.

|

nr 3

147-150

EN

Water has been used as a lubricating medium in a number of applications in tribology. Its insufficient lubricating properties are modified by appropriate additives. The aim of the tribological studies presented in this paper is an application of a mixture containing triglyceride ethoxylates and partial glycerides as well as esters and a block copolymer as additives. All the components are commercially available and relatively cheap. In order to examine the aqueous solutions, two kinds of tests were carried out on a four-ball apparatus: at the fixed load - measurements of the friction coefficient and wear as a function of time and seizure tests which made it possible to determine the scuffing load (Pt), the seizure load (Poz) and the limiting pressure of seizure (poz). Changes in the quantities measured were analyzed as a function of concentrations ranging from 0.001% to 100%. In the fixed load tests the coefficient of friction decreased almost eight-fold, reaching the lowest value of 0.06 at above 0.1% concentration of the additive. Wear decreased over 3.5-fold. In the seizure tests a relatively high efficiency of the additive package was observed at the concentration of the order of the thousandth part of one percent. The compositions reached the maximum anti-seizure capacity at the concentrations of 4 and 10%. It is particularly interesting to note that the stability of the lubricating film being formed was characterized by the scuffing load. The maximum value of Pt was about 4kN high. Summing up, on the basis of the results obtained it may be concluded that the choice of package additives was correct and it effectively modified the lubricating properties of water.

2

New theoretical method for establishing indentation rolling resistance

88%

Konieczna-Fuławka M.

|

2023

|

tom Vol. 30

99--111

EN

Theoretical analysis indicates an underestimation of the calculated values of resistance of conveyor belts in relation to the measurement results. Disproportions are mainly observed for large mass capacities of conveyors. In this paper previous method for calculations of indentation rolling resistance was improved. Indentation rolling resistance is the main component of motion resistance for conveyors longer than 80 m. The most important impact on rolling resistance have damping factor of belt. This parameter was included in calculations in the new approach, moreover, a defined way of its determination in laboratory conditions was indicated. Another important parameter is the modulus of elasticity affecting the transverse rigidity of the belt. By analyzing elastic energy in bottom cover and cord of the belt new equations (which included construction and belt type) were established. In addition, the impact of the distribution of the loads along the idler on the rolling resistance value was analyzed. On this basis different equations for calculations of center and side idler was proposed. New theoretical model was verified in both laboratory test and measurements conducted in mine conditions. A series of tests of rolling resistance and damping properties were carried out for belts of various core designs and various rubber of bottom covers. Damping factors and modules of elasticity established in laboratory conditions were applied to new calculations algorithms. Obtained results were compared with measured values. Final verification of the new theoretical model was a comparison of calculated resistance with measured values for conveyor in mine. The obtained results have much higher convergence than the previous calculations. The new calculations allows for more accurate dimensioning of the drive and other elements of the belt conveyor.

3

Badania eksperymentalne zużycia energii lekkiego pojazdu elektrycznego

75%

Targosz M. , Cichoński K. , Kotysz R. , Gleń M. , Szymon A.

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tom z. 3/99

151--159

PL

W artykule zaprezentowano badania doświadczalne lekkiego pojazdu elektrycznego MuSHELLka skonstruowanego przez zespół SmartPower z Wydziału Mechanicznego Technologicznego Politechniki Śląskiej. Badanie przeprowadzono na Torze Jazd Doświadczalnych fabryki Fiat Auto Poland w Tychach. Przeprowadzono próby swobodnego wybiegu z wykorzystaniem różnego rodzaju ogumienia. Badano dwa możliwe do zastosowania elektryczne układy napędowe - silnik PM BLDC wraz z przekładnią z paskiem zębatym oraz silnik PM BLDC o bezpośrednim przełożeniu zamontowany w piaście koła napędowego. Dane pomiarowe były rejestrowane poprzez mikroprocesorowy układ pomiarowy i zapisywane na karcie SD. Próby terenowe były wykonywane również w celach treningowych kierowców prototypowego pojazdu i umiejętności realizowania strategii przejazdu. Badania doświadczalne posłużą do identyfikacji modelu matematycznego pojazdu oraz do weryfikacji założeń projektowych i wyboru optymalnych rozwiązań w zakresie stosowanych opon i wyboru układu napędowego.

EN

The article presents an experimental investigation of the energy consumption for lightweight electric vehicle MuSHELLka. The vehicle was built by SmartPower team from the Faculty of Mechanical Engineering, Silesian University of Technology. The tests were carried out on the experimental rides track of the Fiat Auto Poland factory, located in Tychy. Tests were conducted with using different types the of tires, and two possible to apply drive systems - a PM BLDC motor with toothed belt transmission, and motor with direct ratio mounted in the wheel hub. The measurement data were acquired by a microprocessor-based measuring system, and saved on the SD card. Experimental studies will be used to identify the mathematical model of the vehicle and to verify the project assumptions and the choice of optimal solutions of tires and the drive units.

4

Metoda doświadczalnego wyznaczania oporów ruchu układu mechanicznego kolei linowych

75%

Magiera T.

|

2013

|

tom z. 98

369--377

PL

W publikacji przedstawiono doświadczalną metodę wyznaczania wartości oporów ruchu niewyprzęganych kolei linowych krzesełkowych. Przedstawiona metoda pozwala na uzyskanie dokładnej wartości współczynnika oporów ruchu i wartości całkowitego momentu bezwładności mas ruchomych, dla konkretnie rozpatrywanego urządzenia. Opracowana metoda została oparta na danych doświadczalnych uzyskanych na eksploatowanych kolejach linowych i poddana procesowi weryfikacji.

EN

The article provides information about full methodology of motion resistance coefficient of a whole fixed-grip ropeway system. The results of the method are getting the exact values of the motion resistance coefficient and momentum of inertia, based on conducted research on chairlifts. The methodology of the both values verification was described as well.

5

Vegetable oils derivatives as the modifiers of the lubricating properties of water

63%

Sułek M. W. , Sas W. , Przondo J.

Polish Journal of Chemical Technology

|

2007

|

tom Vol. 9, nr 3

147-150

EN

Water has been used as a lubricating medium in a number of applications in tribology. Its insufficient lubricating properties are modified by appropriate additives. The aim of the tribological studies presented in this paper is an application of a mixture containing triglyceride ethoxylates and partial glycerides as well as esters and a block copolymer as additives. All the components are commercially available and relatively cheap. In order to examine the aqueous solutions, two kinds of tests were carried out on a four-ball apparatus: at the fixed load - measurements of the friction coefficient and wear as a function of time and seizure tests which made it possible to determine the scuffing load (Pt), the seizure load (Poz) and the limiting pressure of seizure (p(oz)). Changes in the quantities measured were analyzed as a function of concentrations ranging from 0.001% to 100%. In the fixed load tests the coefficient of friction decreased almost eight-fold, reaching the lowest value of 0.06 at above 0.1% concentration of the additive. Wear decreased over 3.5-fold. In the seizure tests a relatively high efficiency of the additive package was observed at the concentration of the order of the thousandth part of one percent. The compositions reached the maximum anti-seizure capacity at the concentrations of 4 and 10%. It is particularly interesting to note that the stability of the lubricating film being formed was characterized by the scuffing load. The maximum value of Pt was about 4kN high. Summing up, on the basis of the results obtained it may be concluded that the choice of package additives was correct and it effectively modified the lubricating properties of water.

6

Uwagi o oporach ruchu w implantach stawów człowieka

63%

Kowal A. , Pytko S.

Tribologia

|

2001

|

tom nr 5

987-1004

PL

W artykule przedstawiono konstrukcję wkładki do stawu biologicznego lub endoprotezy, której zadaniem ma być przedłużenie funkcjonowania stawów biologicznych, w niektórych przypadkach zniszczonych procesem chorobowym lub zmniejszenie zużycia endoprotezy. Wkładka do stawu ma amortyzować obciążenia udarowe i wyrównywać naciski jednostkowe na współpracujących powierzchniach, a przy ograniczonymzakresie względnego ruchu w stawie, wkładka ma też umożliwiać ruch bez poślizgu pomiędzy współpracującymi powierzchniami elementów stawu. Na zaprojektowanym stanowisku doświadczalnym wyznaczono zastępczy współczynnik tarcia przy ruchu kuli stalowej w czaszy wykonanej z poliamidu w warunkach podobnych do pracy endoprotezy. Badania przeprowadzono dla przypadków typowej pracy endoprotezy z różnymi czynnikami smarnymi i dla przypadku zastosowania opatentowanej wg naszego pomysłu, przykładowej konstrukcji wkładki.

EN

In the paper is presented the construction of the insert (fig. 2) for biological human joints (fig. 1) or implants, whos task is to prolong work of biological joints worn after illness or for decrease of existing implants wear. Insert have amortise loads and equalise pressure on cooperating surfaces (fig. 3) and for limited respect could facilitate motion due to making possible motion without sliding beetwen cooperating surfaces (fig. 4). In the designed test stand (fig. 5), the apparent friction coefficient has been determined in the condition similar to artificial joint operation i.e. steel ball on the spherical polyamid bush. Tests were performed with different lubricants with use of our patent pended insert.

7

Opory ruchu powierzchniowych elementów wirujących

63%

Głowacki H.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

|

1999

|

tom z. 52 [174]

147-152

EN

In electro-mechanical devices such as tape or video recorders, moment coming from the engine needed to overcome the motion resistance of the magnetic tape is of the same order of magnitude as the frictional resistance (of the rotating elements) not only in bearings but mainly in the surrounding medium which is air. The author of this paper did not find any materials on the motion resistance of rotating superficial elements in the surrounding gaseous medium. He therefore built the relevant measuring equipment and made a lot of experiments which allowed him to draw interesting conclusions and make some observations. The results of selected measurements of the resistance moment M(op) of the rotational motion of superficial constructional/elements have been drawn in the form of graphs of Mop = f(n) fiunction, where n is the rotational speed of the selected element of disk in revolutions per minute (rpm).