Tj. Royston et I. Basdogan, VIBRATION TRANSMISSION THROUGH SELF-ALIGNING (SPHERICAL) ROLLING ELEMENT BEARINGS - THEORY AND EXPERIMENT, Journal of sound and vibration, 215(5), 1998, pp. 997-1014
Interest in vibration control in systems employing rolling element bea
rings, ranging from rotor systems used in energy conversion/transmissi
on to high-precision, multi-degree-of-freedom optical positioning syst
ems, has focused attention on the modelling of bearing dynamic stiffne
ss properties. While modelling a rolling element bearing either as an
ideal boundary condition for a shaft or as a simple translational elem
ent may suffice in understanding basic rotor system dynamics, such sim
ple models are inadequate in explaining how vibratory energy may be tr
ansmitted from, for example, transverse shaft vibrations to perpendicu
lar, out-of-plane casing vibrations. Recently, researchers have begun
to address this issue for conventional single row ball or cylindrical
rolling element bearings which exhibit a strong moment-coupling stiffn
ess. The study reported in this article focuses on double row spherica
l (self-aligning) rolling element bearings where moment stiffnesses an
negligible, but translational cross-coupling stiffnesses between axia
l and radial bearing directions are present. A new theoretical model f
or the direct and cross-coupling stiffness coefficients of spherical r
olling element bearings is developed and partially validated using new
experimental techniques. It is shown that the coefficient values are
complicated functions dependent on radial and axial preloads. While cr
oss-coupling stiffness coefficients are negligible with simple radial
or axial preloads, under the combined radial plus axial preload condit
ion, the cross-coupling stiffness coefficient between the axial direct
ion and the direction of the radial preload becomes significant. (C))
1998 Academic Press.