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Evaluation of the Influence of the Cooling Method Used During Grinding on the Operating Properties of Ceramic Grinding Wheels Made with Different Abrasives

Stachurski Wojciech, Dębkowski Ryszard, Rosik Radosław, Święcik Robert, Pawłowski Witold

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 3

1--18

EN

This article presents the results of a study of the performance characteristics of ceramic grinding wheels during peripheral grinding of flat surfaces carried out using different methods of supplying cooling and lubricating fluid (coolant). In the study, T1 type grinding wheels were used, differing in the type of abrasive used in their construction. The abrasive consisted of mixtures with different volume percentages of: 1) grains of conventional white electro-corundum, 2) grains of submicrocrystalline sintered corundum produced by sol-gel technology, 3) microcrystalline sintered ceramic grains with RECERAMAX™ RT microclasters from RECKEL. Specimens made of 145Cr6 tool steel (60±1 HRC) were ground using coolant feeding by flood method and MQL (Minimum Quantity Lubrication) method. During the study, the components of grinding force (Fn, Ft), radial loss of the grinding wheel and roughness of the ground surface were measured, which made it possible to determine the volumetric wear of the grinding wheel Vs, the total grinding power P, and then calculate the grinding indicators G and Ks. The obtained values of the G index indicate that, regardless of the type of grinding wheel used, a higher relative grinding efficiency was obtained during grinding with the delivery of coolant by the MQL method. The highest values of this index were obtained in the case of the grinding process carried out with a grinding wheel containing RECERAMAX™ RT abrasive. The Ks index confirmed the best performance of the mentioned grinding wheel. Since its value also depends on the total grinding power P and the surface roughness parameter Ra, the grinding process carried out with this grinding wheel is additionally characterized by a better quality of the obtained surface and lower energy consumption.

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Pneumatic actuator positioning with pilot controlled check valves

Pawłowski Witold, Małek Adrian, Sikorski Jakub

Mechanics and Mechanical Engineering

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2021

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Vol. 25, nr 1

15--21

EN

Tests of accuracy and repeatability of the pneumatic cylinder positioning in intermediate positions using a check valve are presented. The tests were performed under different loads and for different piston speeds and operating pressure in a pneumatic system with throttle check valves and an optical linear displacement sensor measuring the position of the actuator rod. Assessment of the effect of the cylinder performance parameters on the accuracy and repeatability of piston rod positioning was done and limitations and possible applications of the pneumatic cylinder positioning in intermediate positions with a check valve were identified.

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Dynamic properties of hybrid machine tool body - theoretical and experimental investigation

Kępczak Norbert, Pawłowski Witold

Mechanics and Mechanical Engineering

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2021

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Vol. 25, nr 1

6--14

EN

The article presents theoretical and experimental investigation in order to obtain dynamic properties of hybrid machine tool body in comparison with cast iron body. For this purpose, the theoretical and experimental modal analyses were carried out. The influence of the mineral cast material for filling voids on the dynamic properties of the machine tool body was discussed. During the analysis, the modes and frequencies of free vibrations, the amplitude values and the damping ratios were compared. Despite lowering the free vibration frequency of the hybrid construction, compared to the cast iron body, in some cases, the dynamic propertieswere affected. This could be determined on the basis of decreasing the amplitude value of the transfer function (from 12.16% to 58.66%) and the increasing the vibration damping coefficient ratio (from 12.22% to 75.24%) in the case of a hybrid body as compared to a cast iron body. The final conclusions were drawn about the application of mineral casts in the construction of machine tools and its impact on the dynamic properties of the structure.

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Urazowość w wypadkach drogowych w Polsce

Goniewicz Krzysztof, Goniewicz Mariusz, Pawłowski Witold

Transport Miejski i Regionalny

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2019

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nr 1

15--18

PL

Celem badania była ocena skutków oraz czynników mających wpływ na wypadki drogowe w ruchu samochodowym w latach 2004–2014 w Polsce. Badanie opierało się na analizie danych zawartych w raportach Biura Prewencji i Analiz Komendy Ruchu Drogowego Policji, Narodowego Programu Bezpieczeństwa Ruchu Drogowego – GAMBIT 2005, Narodowego Programu Bezpieczeństwa Ruchu Drogowego 2013– 2020, Strategii Sprawnego Państwa 2020 r. oraz publikacji obrazujących główne problemy bezpieczeństwa drogowego w Polsce. W Polsce wypadki drogowe są pierwszą przyczyną śmierci mężczyzn w wieku do 44 lat. Najczęstsze, powtarzające się przyczyny wypadków drogowych to nieprzestrzeganie zasad ruchu drogowego, niskie umiejętności prowadzenia pojazdu połączone ze słabą oceną sytuacji na drodze, brakiem odpowiedniej infrastruktury drogowej oraz złymi warunkami technicznymi pojazdów. Pomimo różnorodności działań podejmowanych w celu poprawy bezpieczeństwa na polskich drogach liczba ofiar śmiertelnych i rannych w wypadkach samochodowych jest nadal znaczna, a straty ponoszone przez społeczeństwo polskie są wysokie. Konieczne jest kontynuowanie wielokierunkowych działań mających na celu poprawę bezpieczeństwa na drogach w Polsce, skutkujących systematycznym zwiększaniem poziomu bezpieczeństwa ruchu drogowego.

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The research aims at assessing the prevalence, effects as well as risk factors for motor vehicle traffic accidents (MVA) in year’s 2005 to 2014 in Poland. The research is based on the analysis of dense data contained in the reports of Prevention and Analysis Office of Road Traffic Headquarters of Police; National Road Safety Program – GAMBIT 2005, National Road Safety Program 2013 to 2020; Strategy for the Efficient State in 2020 as well as few publications depicting the main problems of road safety in Poland. In Poland, road accidents are the first cause of death in case of men up to 44 years. The most common, permanently occurring causes of road accidents include failure to comply with the rules of the road traffic, low driving skills combined with a poor assessment of the situation on the road, lack of adequate road infrastructure as well as poor technical conditions of vehicles. Despite the variety of measures undertaken to improve safety on Polish roads, the number of fatalities and injuries resulting from motor vehicle accidents is still considerable, and the losses incurred by Polish society are still substantial. It is necessary to continue multidirectional actions to improve safety on the roads in Poland, resulting in a systematic increase in the level of road traffic security.

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Przekładnia planetarna do napędu śmigła w nowej generacji modeli latających

Sikorski Jakub, Pawłowski Witold, Kaczmarek Łukasz, Stegliński Mariusz, Lipa Sebastian, Klich Marek

Mechanik

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2019

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R. 92, nr 4

282--284

PL

W artykule przedstawiono projekt przekładni planetarnej, która w połączeniu z silnikiem elektrycznym zapewni zwiększony moment obrotowy, umożliwiający napędzanie dużych, wysoko sprawnych śmigieł nowoczesnych modeli latających. Zaproponowane rozwiązanie pozwala na zastosowanie standardowych wysokoobrotowych silników prądu stałego lub silników bezszczotkowych. Dodatkowo nowatorska konstrukcja przekładni gwarantuje wysoką sztywność mechanizmu, niezbędną do przeciwdziałania efektom żyroskopowym generowanym przez duże śmigło. Zastosowanie stopu aluminium o wysokiej wytrzymałości przyczynia się do utrzymania niskiej masy całego mechanizmu.

EN

The article presents a planetary gear design, which in combination with an electric motor will allow to obtain an increased torque enabling the propulsion of large, high-performance propellers of modern flying models. The proposed solution allows the use of standard high-speed DC or brushless motors. In addition, the innovative design of the transmission provides high stiffness of the mechanism necessary to counteract the gyroscopic effects generated by the large propeller. The use of high-strength aluminum alloy ensures low weight of the entire mechanism.