Abstract
The influence of the different distributions of magnetic fields on the dynamic performances of the journal bearing lubricated with ferrofluid is investigated through numerical simulation. It is found that the dynamic performances of the journal bearing, such as the stiffness coefficients, the damping coefficients and the stability, have strong dependence on the distribution of the magnetic field in the clearance of the bearing. The influence of the angular momentum of the particles in ferrofluid on the performances of the bearing has the same order as that of the magnetic force in the case that the magnetic field distribution is inhomogeneous both in the axial direction and in the radial direction of the bearing, while a lot of former researches ignore the angular momentum of the particles and suppose a parabolic distribution of magnetic field. Moreover, the larger the magnetic intensity is, or the smaller the eccentricity of the bearing is, or the lower the rotation speed of the shaft is, the larger the effect of the magnetic field on the dynamic performances of the bearing becomes.
