Effect of dynamic misalignment on the vibration response, trajectory followed and defect-depth achieved by the rolling-elements in a double-row spherical rolling-element bearing.

• Balls of misaligned bearing either follow offset or inclined trajectories. • Increase in radial and axial load has contrasting effect on vibrational response. • Vibrational response is more sensitive to offset case than inclined case. • Effect of defect's dimension and misalignment on depth achieved by balls analyzed. • System shows an intermittent behaviour with multi-periodicity having hidden chaos. Dynamic-misalignment beyond a specific limit suggests some abnormal systems' behaviour and, if not dealt with appropriately may lead to its sudden breakdown. To address this problem spherical rolling-element bearings are used which have the capacity to encounter such misalignment till a certain limit. Investigating this physical mechanism of such bearing's and quantifying the degree as well as nature of dynamic-misalignment can lead to diagnosing the root cause responsible for it. This paper thus aims at understanding the physics governing the vibration response of spherical rolling-element bearing with a localized defect and subjected to dynamic-misalignment at the same time, using numerical simulations and experimental validation. The numerically simulated results firstly show that an increase in radial and axial loads have a contrasting effect on the acceleration response and contact-load shared by the two bearing rows. Secondly, the rolling-elements while following an offset trajectory, significantly affect the bearing's vibration response as compared to an inclined trajectory and the depth achieved by rolling-elements inside defect also varies with varying misalignment angles. Thirdly. with an increase in misalignment, the strange attractors form intermittent behaviour with outer multi-periodic response having hidden chaos. The behaviour observed from the numerically simulated results was also validated from the vibration data obtained experimentally from the test-rig. [ABSTRACT FROM AUTHOR]