Frictional properties evaluation for friction couples in a V-shaped damping unit of a freight-car bogie

Solution of a problem to improve reliability and durability of the freight-car bogies depends largely on success in securing high functional capability of the damping unit primarily by use of new materials at the stage of its manufacture. When using in manufacture of a damping unit for the freight-car bogie any new materials or new technologies for their production we are not always able to calculate their frictional properties in accordance with specified parameters. Employment of in-situ testing, rig tests and running tests in estimating frictional properties of V-shaped damping units made of various materials allows to fully compare realistic parameters of tribological behavior of the unit with various friction couples while imitating actual conditions of the rolling stock operation. Comparative analysis of calculation results and measurements of the relative friction coefficient for the ‘friction wedge/friction plate’ couple used in a V-shaped damping unit in order to damp oscillations of the spring suspension obtained during field tests allowed us to validate practicability and efficiency of employing rig tests to measure parameters of tribological behavior of friction couples when performing comprehensive tests of usage variants in relation to new materials for the freight-car bogie damping unit.

freight car, bogie, V-shaped damping unit, friction wedge, friction plate, frictional properties, relative friction coefficient, gray cast iron grade SCh35, cast iron grade XhMN-35M, steel grade 30KhGSA, steel grade 25Kh

1. Chelnokov I. I. et al. Gasiteli kolebaniy vagonov [Train cars vibration dampers]. Moscow, Transzheldorizdat Publ., 1963. 176 p.

2. Kragel’skiy I. V. Trenie i iznos [Friction and wear]. Moscow, Mashinostroenie Publ., 1968. 480 p.

3. Chichinadze A. V. et al. Trenie, iznos i smazka (tribologiya i tribotekhnika) [Friction, wear and lubrication (tribology and triboengineering)]. Moscow, Mashinostroenie Publ., 2003. 576 p.

4. Markov D. P. Tribologiya i ee primenenie na zheleznodorozhnom transporte [Tribology and its application in rail transport]. Moscow, Intext Publ., 2007. 408 p. (Proc. of the Railway Research Institute).

5. Efimov V. P., Pranov A. A. Modernizatsiya telezhki modeli 18-100 — effektivnyy put’ povysheniya bezopasnosti dvizheniya poezdov [Modernization of the bogie model 18 – 100 — an effective way to increase the safety of trains]. Tyazheloe mashinostroenie, 6. Chelnokov I. I. et al. Osnovnye napravleniya sovershenstvovaniya i razrabotki ressornogo podveshivaniya vagonov dlya perspektivnykh usloviy ekspluatatsii [The main areas of improvement and development of spring suspension of cars for prospective operating conditions]. Trudy LIIZhT [Proc. of Leningrad Inst. of Transport Engineers], 1966, no. 255, pp. 28 – 45.

6. Norms for calculation and design of cars for MR 1520 mm gauge railways (unpowered). Moscow, GosNIIV, VNIIZhT Publ., 1996. 319 p. (in Russ.).

7. Velikanov A. V. et al. Chugunnye friktsionnye klin’ya telezhki gruzovogo vagona [Cast iron friction wedges of freight car bogies]. Vestnik VNIIZhT [Vestnik of the Railway Research Institute], 1999, no. 1, pp. 25 – 31.

8. Velikanov A. B, Borshch B. V. Friktsionnye klin’ya iz vysokoprochnogo chuguna [Friction wedges of ductile cast iron]. Vestnik VNIIZhT [Vestnik of the Railway Research Institute], 2007, no. 2, pp. 18 – 22.

9. Velikanov A. B, Borshch B. V. Klin iz serogo chuguna dlya friktsionnogo gasitelya kolebaniy gruzovykh vagonov [Wedge of gray cast iron for the friction damper of freight cars]. Voprosy razvitiya zheleznodorozhnogo transporta v usloviyakh rynochnoy ekonomiki. Sb. nauch. tr. OAO “VNIIZhT” [Issues of railway transport development in a market economy. Coll. of sci. works of JSC «VNIIZhT» (Railway Research Institute)]. Moscow, Intext Publ., 2007, pp. 166 – 175.

10. Gabets A. V. Spetsial’nyy chugun dlya otlivki friktsionnogo klina telezhki zheleznodorozhnogo vagona [Special iron for casting friction wedge of railway car truck]. Polzunovskiy vestnik, 2013, no. 4/2, pp. 51 – 52.

11. Filippov G. A. Fundamental’nye issledovaniya prirody khrupkosti — osnova sozdaniya vysokoprochnykh i nadezhnykh konstruktsionnykh materialov [Fundamental studies on the nature of fragility — the basis for the creation of high-strength and reliable construction materials]. Stal’, 2004, no. 8, pp. 69 – 78.