Mathematical modelling of thermal behaviour of cylindrical roller bearing for towed railway vehicles

Abstract

Preliminary communicationThis paper presents a mathematical model for the prediction of the thermal behaviour of a cylindrical roller bearing for axle assembly of the wheel set of the towed railway vehicles. The mathematical model allows for the heat generated due to lubrication, radial and axial loads at different speeds of the train to be calculated. The method of calculating of the heat conducting and converting coefficients in the bearing is also shown. By using the general purpose software system based on the finite elements method, the thermal behaviour of the above mentioned cylindrical roller bearings was analysed. Temperature values of the bearings are determined by the finite elements method values depending on the speed of the train movement on a straight-line section and the curve (v = 20 km/h, v = 40 km/h, v = 60 km/h, v = 80 km/h and v = 100 km/h), the curve radius (R = 500 m), the ambient temperature of 20 °C and the cant height (h = 110 mm, h = 140 mm, h = 180 mm). Keywords: cylindrical roller bearing for towed railway vehicles; finite elements method; mathematical modelling Matematičko modeliranje toplinskog ponašanja valjnog ležaja s valjčićima za vučena željeznička vozilaPrethodno priopćemje U radu je prikazan matematički model za predviđanje toplinskog ponašanja valjnog ležaja s valjčićima za uležištenje vučenih željezničkih vozila. Matematički model omogućava izračunavanje generirane topline uslijed podmazivanja, radijalnog i aksijalnog opterećenja za različite brzine gibanja vlaka. U radu je također prikazan način izračunavanja koeficijenata provođenja i prevođenja topline u ležaju. Uporabom programskog sustava opće namjene na bazi metode konačnih elemenata analizirano je toplinsko ponašanje valjnog ležaja s valjčićima za vučena željeznička vozila. Metodom konačnih elemenata određene su vrijednosti temperature ležaja u ovisnosti o brzini gibanja vlaka (v = 20 km/h, v = 40 km/h, v = 60 km/h, v = 80 km/h i v = 100 km/h), polumjera zakrivljenosti zavoja (R = 500 m), ambijentalne temperature od 20 °C i visine nadvišenja pruge u krivini (h = 110 mm, h = 140 mm, h = 180 mm). Ključne riječi: vmatematičko modeliranje; metoda konačnih elemenata; aljni ležaj s valjčićima za vučena željeznička vozila

Analysis on Damage to Rolling Bearings at Small Turning Angels

“…Finally, a rolling implementation of the rotation point was developed, despite the known lubrication problems with small turning angles. Friction losses are smaller in rolling implementation, and heat load of the rotation point is also smaller [7]. Energy efficiency of this test rig was analysed in paper [8].…”