Journal and Thrust Bearings
Misalignment in journal and thrust bearings acts as preload on the rotor and has a similar effect as predeformation in springs. Therefore, modeling of the misalignment requires adjustment of the relative motion between the journal and the foundation motion. Let
u
r
and
u
f
be the journal and foundation displacements at the bearing center, and
θ
r
and
θ
f
be the tilt angles of the rotor and foundation. For a parallel misalignment
u
0
, the relative displacement between the journal and foundation is given by
For an angular misalignment
θ
0
, the relative angular displacement between the journal and foundation is
The spring and damping forces are then functions of these relative displacements, rotations, and their derivatives.
For details about the bearing forces, see the theory for the
Journal Bearing
and
Thrust Bearing
.
