Piston eccentricity and friction force measurement in a hydraulic cylinder in dynamic conditions considering the form deviations on a piston

Geometrical imperfections on pistons cause an asymmetric pressure distribution in the clearance between the piston and cylinder bore. Due to this, the piston attains different eccentricity positions during a stroke. The eccentricity of the piston affects the performance of the cylinder by influencing the frictional and leakage aspects. A compact mechatronic test rig is designed and fabricated to measure the piston eccentricity and friction in a dynamic condition. Pistons of defined geometric profiles such as elliptic and three-lobe are fabricated using a machining center. These pistons have been introduced into the test rig. The eccentricity and dynamic friction tests are conducted at various operating conditions and the results are presented and analyzed.