To prevent shortage of a discharge amount of a pump of a smaller discharge amount, even if the discharge amount is different between a front pump and a rear pump.

One pump is made to have a discharge amount than that of the other pump. On the other hand, a center plate 1 comprises a first flow passage 30 connecting a tank with an intake port of a front pump and a second flow passage 31 connecting the tank to an intake port of a rear pump. When a shaft 4 is rotated to drive both of the pumps, working fluid is led from the tank to the intake port of the front pump through the first flow passage 30, and working fluid is led from the tank to the intake port of the rear pump through the second flow passage 31.