LIFTING DEVICE

PROBLEM TO BE SOLVED: To provide a high-output lifting device having a stable lifting part and capable of reducing its weight and size. SOLUTION: A structure 2 as the lifting part is liftably supported by four lifting legs 4a to 4d, and a screw type cylinder 10 telescoping by rotation, electric motors 7a to 7d and encoders 8a to 8d are provided to the respective lifting legs 4a to 4d. A control device 20 sets the rotation speed of the electric motor having the slowest rotation speed according to signals from the respective encoders 8a to 8d as a reference value, and controls the other electric motors so as to lower the rotation speed to the reference value. Thereby, the respective electric motors 7a to 7d are synchronously operated with the rotation speed of the reference value and the displacement quantity of the four lifting legs 4a to 4d can be leveled to achieve stable lifting operation. Also, since the plurality of electric motors 7a to 7d are adopted, high output and reduced weight and size can be achieved in the device as a whole. COPYRIGHT: (C)2010,JPO&INPIT