Patent ID: 7067999

Claim:
A rotation control device for a working machine, the device comprising: an electric motor for rotatably driving a rotating body; operation means for issuing a rotation command for rotation of the rotating body; control means for controlling said electric motor based on the rotation command issued from said operation means; a rotating speed detecting means for detecting a rotating speed of the rotating body; and a mechanical brake for generating mechanical braking force, wherein said control means has a neutral range set by adding a predetermined width to an absolute neutral point serving as a basic point, the absolute neutral point corresponding to an operation amount of said operation means of zero, and in said neutral range, a mechanical brake zone is set on the absolute neutral point side, while a position holding control zone is set on a side opposite to said neutral point side, and wherein said control means is adapted to cause said mechanical brake to work in the mechanical brake zone of said neutral range, to perform position holding control in said position holding control zone, thereby stopping and holding said rotating body, and to perform speed control according to the operation amount of said operation means outside the neutral range.