Mechanical gravity canceller with oscillating block slider crank mechanism

In this paper, we propose a passive gravity compensation mechanism with a slider crank mechanism and a compression spring, which named "Compression Type Mechanical Gravity Canceller (CT-MGC) ". The CT-MGC has several advantages in comparison with the original MGC. First, the new mechanism generates accurate weight compensation torque as same as the MGC without wire and pulley, because it consists of rod-driven mechanism. Second, the new mechanism can be installed into heavy manipulators or carry heavy loads while ensuring high rigidity and safety, since there is no risk for amputation of wire. From development and experiments of a single link model equipped with the CT-MGC, it is clarified that this revolutionary device succeeds to shift basic concepts of weight compensation mechanism from "raise tension" to "push up".