1988 Volume 54 Issue 507 Pages 2771-2780
The stiffness and damping coefficients of oil film in porous oil journal bearings with nonuniform permeability, and the vibrational stability of a shaft supported by these are theoretically investigated. Three types of nonuniform distribution of permeability are analyzed. For the first type, the permeability of the inside part is lower than that of the outside part. For the second type, the permeability of the loaded part is lower than that of the unloaded part. For the third type, the permeability of part of the bearing ends is lower than that of the middle part. All nonuniform types have larger oil film coefficients, in which the cross-coupled stiffness term KXY is larger in magnitude, together with a greater stability threshold speed than a uniform type in which the permeability is equal to the higher one of nonuniform types. Moreover, the first type has a greater stability threshold speed within a high bearing modulus λ(λ=So/ν, So : Sommerfeld number. ν : nondimensional shaft rotational speed), and the second type has a higher one within a low bearing modulus.
Transactions of the Society of Mechanical Engineers
Transactions of the Japan Society of Mechanical Engineers
Transactions of the Japan Society of Mechanical Engineers Series A
Transactions of the Japan Society of Mechanical Engineers Series B
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A
