In the kinematic chain of the manipulator of hydraulic excavators, the drive of the revolute pairs is carried out by a hydraulic cylinder hinged to the two links of the pair, which realizes a planar drive mechanism of the type Inverted Slider-Crank Mechanism, centric type (ISCM). The power capabilities of the ISCM are described by the basic mechanism transfer function dS/dφ, which fully describes the driving moment of the ISCM in dimensionless form. The present work addresses the task of synthesizing the mechanisms with hydraulic cylinders (ISCMhc), of a two-link planar manipulator for lifting a load of weight G at different points of the workspace. The motion is assumed to be at low speed and no dynamic loading is considered. A solution to the problem is given for each mechanism ISCMhc separately, passing through several stages: preliminary selection of the small parameter λ of the ISCM, determination of the external load of the cylinders and its normalization to the power capabilities of the ISCM in a dimensionless form, determination of the required force of the hydraulic cylinders, determination of the angles and dimensions of ISCM and cylinder stroke check. Finally, an example with specific input data is given. The proposed methodology for the synthesis of ISCMhc appropriately takes into account the power specifics of the considered mechanism, as the known external load fits into the main transfer function of the mechanism dS/dφ, without exceeding it, thus guaranteeing the performance of the task for the entire working range of the manipulator.

synthesis, inverted slider-crank, drive mechanism, manipulator, hydraulic excavators