Gravity Compensator for Exoskeleton Based on Elastic Hinges with a Given Characteristic

The paper is devoted to the development of a gravity compensator based on elastic hinges with a given characteristic for holding objects weighing several tens of kg. A joint with a given characteristic is a structure in which an elastic element (spring or pneumatic spring) moves between the guides of the calculated shape. The characteristics (dependence of the restoring moment of the hinge on the angle of its rotation) of two elastic hinges connecting the rods of a gravity compensator are calculated so that at almost any angle of rotation of the hinges, the object held with a given weight will be in equilibrium. The calculation of the shape of elastic joint guides is given to obtain a given dependence of the restoring moment on the angle of rotation of the joint. A spring and a pneumatic spring are considered as the elastic element of the hinge. It is established that it is possible to provide a given change in the weight of the held object by calculating the pressure change in the pneumatic spring. The considered gravity compensator can be used when working with heavy tools.