PURPOSE: To prevent a deterioration of efficiency for a machine and a generation of its vibration and noise, by providing balancing holes for balancing inner and outer pressure of a liner in the insides of pressure chambers at the side of static pressure.

CONSTITUTION: Balancing holes 7, 8 for balancing inner and outer pressures in liners 5, 6 are provided on radiuses R1, R2 at the side of inside diameters r1, r2 of the liners 5, 6. In this way, a smooth state of flow movement around a runner 2 as shown by q1, q2, q3, q4, q5 causes no secondary flow in pressure chambers IV, V, thus capable of preventing a deterioration of efficiency of a machine and a generation of its vibration and noise.