Research of the force characteristics of hydraulic cylinder type loading devices for exercise machines

  • A. Domeika
  • V. Eidukynas Kaunas University of Technology
  • V. Grigas Kaunas University of Technology
  • A. Šulginas Kaunas University of Technology
Keywords: hydraulic cylinder, exercise machine, resistance force, piston speed

Abstract

Experimental research of hydraulic cylinder type resistance devices at different operating regimes (piston speed and resistance level) has been performed by means of universal computer controlled benchtop materials test-ing machine “Tinius Olsen H25K-T”. The samples were taken from different brands exercisers where resistance is generated by the pair of cylinders: three mini steppers and three rowing exercisers (these with manually adjustable resistance). The research showed that hydraulic cylinder type loading devices of exercise machines generate quite uneven resistance force: depending on the operation re-gime its variation reaches up to 30 % of nominal size. Ac-cording to the results of investigation it may be stated that the nominal resistance force depend on the cylinder used (is different for the same design cylinders of different ven-dors), so it is important to use proper cylinder when replac-ing broken or worn unit or even both cylinders have to be replaced to ensure symmetry of resistance.

DOI: http://dx.doi.org/10.5755/j01.mech.20.5.8425

Published
2014-10-30
Section
DESIGN AND OPTIMIZATION OF MECHANICAL SYSTEMS