To provide a highly efficient generator using hydraulic pressure of a small-scale water pipe without distribution of the hydraulic pressure, so that the generator is convenient when lifting a wheelchair or helping a disabled person taking a bath at home.

Piston rods 2, 12 of a plurality of piston cylinders 1, 11 are operated by using the hydraulic pressure of the water pipe so that the phases of the piston rods 2, 12 are shifted. By using it as a power source, crankshafts 4, 14 are rotated, the rotation is transmitted to the generator 10 by a speed-up gear 8 connected to one end of the crank shaft to give appropriate rotation to the generator 10 and generate power.