Actuator device, power assist robot and humanoid robot

An actuator device driven by fluid pressure, comprising:

• a fluid pressure artificial muscle having fixed first end, a second end opposite to the first end, the artificial muscle contracting in a longitudinal contraction direction with increase of said fluid pressure introduced from outside to a fluid bladder for driving;
• a flexible cable for transmitting contraction force of said fluid pressure artificial muscle from the second end of said fluid pressure artificial muscle to an object to be driven;
• a stopper fixed at a prescribed position on said cable;
• an engaging member provided on the second end of said fluid pressure artificial muscle for transmitting the contraction force of said fluid pressure artificial muscle to said cable by engaging with said stopper in response to contraction of said fluid pressure artificial muscle being a prescribed amount or larger;
• and
• a resilient tensioner applying tensile force to said cable in the longitudinal contraction direction of said fluid pressure artificial muscle to maintain tension, thus preventing slacking of the cable when the artificial muscle is not contracted, said fluid pressure artificial muscle including, a cylinder provided in said fluid pressure artificial muscle, fixed to said other end of said fluid pressure artificial muscle and having the inside sealed from said fluid pressure;
• wherein said engaging member is a lid of said cylinder provided at said other end of said fluid pressure artificial muscle, said lid having a through hole through which said cable passes, said stopper is fixed to said cable inside said cylinder, has an outer diameter not smaller than said through hole and is engageable with said through hole, and said resilient tensioner coupling said stopper with a bottom portion of said cylinder.