Modelling of damping in lubricated line contacts – Applications to spur gear dynamic simulations

Abstract

The various damping mechanisms in elasto-hydrodynamic lubrication contacts are investigated with the objective of deriving damping models representative of the lubricant contributions which can readily be used in gear dynamic simulations. Several simplified models are proposed which make it possible to simulate the damping caused by tooth friction and lubricant squeezing by the teeth with and without momentary contact losses and impacts. A one-degree-of-freedom gear dynamic model is set up which combines these lubricant damping sources along with structural damping. A number of comparisons with benchmark experimental evidence are presented for a range of operating conditions and gear geometries which prove that the proposed approach is sound in the case of spur gears. It is shown that the damping associated with lubricant squeezing contributes for the most part when contact losses and shocks between the teeth occur at critical speeds. For permanent contact conditions, however, structural damping appears as the major contributor to the overall system damping.

Normal and tangential oil film stiffness of modified spur gear with non-Newtonian elastohydrodynamic lubrication

“…Venner investigated the roughness amplitude reduction for EHL point contacts by Ree-Eyring model [10] and Liu studied starved lubrication of a spur gear in Ree-Eyring fluid lubrication [11]. Recently, Kahraman and Lubrecht investigated oil film damping based on Ree-Eyring model [12,13].…”

“…In gear dynamics, the contact stiffness of mesh teeth with lubricant was determined by experience [19]. However, the mesh time-varying stiffness of oil film was a critical factor for revealing the dynamic response of gear drive [13]. Qin et al studied the normal stiffness of elastohydrodynamic line contact with various radii of curvature, loads and entrainment velocities, and also investigated the critical condition in which the elastohydrodynamic stiffness could be approximated by Hertzian stiffness [20].…”

Gear transmission rattle: Assessment of meshing forces under hydrodynamic lubrication

“…In this regard, the role played by the lubricant in these gear pairs through its impact on the determination of dynamic loads in the contact areas is a crucial aspect and has been identified by the research community since the early works. Despite this recognition, accurate modeling of different damping mechanisms linked with the lubricant has received little attention in contrast to the large number of studies that have addressed the study of the dynamic behavior [1,18,23,26].…”

Influences of transient impact and vibration on the lubrication performance of spur gears

“…Ankouni et al. 28 and Huang et al. 29 studied dynamic responses of spur gear pairs by establishing time-varying lubrication damping model.…”