Chinese Journal of Theoretical and Applied Mechanics ›› 2021, Vol. 53 ›› Issue (1): 248-259.DOI: 10.6052/0459-1879-20-261

• Dynamics, Vibration and Control • Previous Articles     Next Articles

NONLINEAR THERMAL ANALYSIS FOR THE INTER-SHAFT BEARING UNDER THE DYNAMIC LOAD 1)

Gao Peng2)(), Hou Lei3)(), Chen Yushu   

  1. School of Astronautics, Harbin Institute of Technology, Harbin 150001, China
  • Received:2020-07-31 Accepted:2020-11-13 Online:2020-12-31 Published:2020-12-31
  • Contact: Gao Peng,Hou Lei

Abstract:

As an important supporting part between the higher pressure rotor and the lower pressure rotor in a dual-rotor system, inner and outer races are rotating with the lower and higher pressure rotors, the heat transfer of the inter-shaft bearing is more prominent. This paper studies the nonlinear thermal behaviors of the inter-shaft bearing under the nonlinear dynamic load. The dynamic load of the inter-shaft bearing is defined based on the dynamic responses of the dual-rotor system, where the nonlinear factors of the inter-shaft bearing such as the radial clearance, the fractional exponential nonlinearity and the parameter excitation are taken into consideration. Thus the nonlinear behaviors such as the jump and the bi-stable phenomena happen to the dynamic load. According to Palmgren's empirical formula, a heat transfer model of the inter-shaft bearing under the dynamic load is established with considering the viscosity-temperature relationship of the lubricant. Steady-state temperatures of the inter-shaft bearing are obtained by the numerical integration. It shows that the nonlinear thermal behaviors of the inter-shaft bearing such as the jump and the bi-stable phenomena are caused by the nonlinear behaviors of the dynamic load. Furthermore, effects of the rotation speed ratio, the unbalances, the inter-shaft bearing's radial clearance, Hertz contact stiffness and roller number on the temperatures and the nonlinear thermal behaviors of the inter-shaft bearing are analyzed. The results show that the unbalances, the radial clearance and the stiffness only affect the nonlinear thermal behaviors of the inter-shaft bearing; the rotation speed ratio and the roller number have a magnificent influence on both. This discovery implies that the dynamic load is more appropriate to describe the actual load of the inter-shaft bearing than the static load. The thermal behaviors of the inter-shaft bearing become nonlinear, which is much more complicated than before, due to nonlinear dynamic characteristics of the dual-rotor system.

Key words: inter-shaft bearing, dynamic load, dual-rotor, jump phenomenon, bi-stable phenomenon

CLC Number: