Prediction of belt sag on a non-motorized curved treadmill

Sayup Kim, Joonho Hyeong, Jongryun Roh, Ohung Kwon, Youngho Kim

Research output: Contribution to journalArticlepeer-review


A non-motorized curved treadmill is completely self-powered equipment operated by human movement. As a walkway, the top surface of its belt has U-shaped concave sag that enables the belt to rotate freely through human footsteps. The concave sag on the upper belt is produced by also allowing the unnecessary sag on the lower belt, which is yet to be known. This study suggests a design method for the curved treadmill accompanied by a mathematical model that enables the prediction of the exact extent of the upper and lower belt sags according to design factors. The mathematical model is presented using the approximated parabola curve instead of the catenary curve, the belt tension, and the wheel friction. An experimental belt system is produced. The extent of the upper and lower belt sags is also measured to compare with the calculated values from algebraic expressions. The theoretical values match the actual measurements, which confirm the validity of the mathematical model. The results of this study will be useful in designing curved treadmills with various geometries.

Original languageEnglish
Pages (from-to)359-365
Number of pages7
JournalInternational Journal of Precision Engineering and Manufacturing
Issue number3
StatePublished - Mar 1 2017
Externally publishedYes


  • Belt sag
  • Catenary
  • Conveyer belt
  • Curved treadmill
  • Non-motorized
  • Parabola


Dive into the research topics of 'Prediction of belt sag on a non-motorized curved treadmill'. Together they form a unique fingerprint.

Cite this