Abstract: In the integrated hydraulic rotary actuator according to the present invention, a valve, a sensor, a controller, and a driving unit for controlling the rotary actuator are integrated, so wires connecting them are not exposed to the outside. Accordingly, it is possible to prevent damage due to interference in operation and maintenance is easy. Further, since it is integrated, including a controller, when the actuator according to the present invention is used, connecting with other parts is easy and interference can be reduced. Therefore, it is easy to design and manufacture a resultant product.

Abstract: In the integrated hydraulic rotary actuator according to the present invention, a valve, a sensor, a controller, and a driving unit for controlling the rotary actuator are integrated, so wires connecting them are not exposed to the outside. Accordingly, it is possible to prevent damage due to interference in operation and maintenance is easy. Further, since it is integrated, including a controller, when the actuator according to the present invention is used, connecting with other parts is easy and interference can be reduced. Therefore, it is easy to design and manufacture a resultant product.

Abstract: A six-degree-of-freedom parallel mechanism is provided for expanding a grade of a spindle. The parallel mechanism has a spindle that turns round a workpiece at a tilting angle of 90.degree. in a workspace, to thereby allow a machining for both vertical and horizontal planes of the workpiece, and a vertical turning process, by a single machining center. A six-axis multi-machining type machining center embodying the parallel mechanism of the present invention is also disclosed. An over-actuated multi-machining type machining center further including over-actuated actuators is presented to solve a problem of driving joints' singularity caused by the parallel mechanism.