Abstract
A viscous flow squeezed between a moving flat disk and a stationary one, whose radii are finite, is studied theoretically. Then, assuming that the ratio of the gap between two disks to their radii is small, an approximate solution is found in the form of the power series of the ratio with the precision of the fourth order of its ratio, because the governing equations represented in the dimensionless form consist of the various terms up to the fourth power of the ratio. The general formulas of the velocity, the pressure, the forces acting on the disks and so on are found from the approximate solution obtained here and compared with the results obtained by other workers.