Fig 1.
Flowchart of this research work.
Fig 2.
Schematic of the experimental apparatus.
(a) Measuring circuit. (b) Experimental apparatus.
Fig 3.
Schematic of the hydraulic cylinder system and its key dimensions.
Table 1.
Main instruments used in the experimental setup.
Table 2.
Key design parameters of the prototype.
Table 3.
Parameters of the O-ring.
Fig 4.
Steady-state friction forces recorded with O-rings of different hardness during reciprocating movements with different frequencies.
Fig 5.
Steady-state friction force with O-ring grooves of different inner diameters under different frequency conditions.
Fig 6.
Example data of dynamic friction measurement.
(a) Displacement signal. (b) Dynamic friction signal.
Fig 7.
Dynamic friction forces of O-rings with different hardness values vs. piston displacements at different reciprocating frequencies.
(a) 60SH.A. (b) 70SH.A. (c) 90SH.A.
Fig 8.
Dynamic friction force with O-rings of different hardness values vs. piston displacement at 4.0Hz reciprocating frequency.
Fig 9.
Dynamic friction forces recorded for O-rings with different hardness values under different maximum displacement conditions at 2.0Hz reciprocating frequency.
(a) 60SH.A. (b) 70SH.A. (c) 90SH.A.
Fig 10.
Dynamic friction force with different O-ring groove inner diameters vs. piston displacement at different reciprocating frequencies.
(a) d = 34.45mm. (b) d = 34.10mm. (c) d = 33.75mm.
Fig 11.
Dynamic friction force with different O-ring groove inner diameters vs. piston displacement at 4.0Hz reciprocating frequency.
Fig 12.
Dynamic friction force with different O-ring groove inner diameters under different maximum piston displacements at 2.0Hz reciprocating frequency.
(a) d = 34.45mm. (b) d = 34.10mm. (c) d = 33.75mm.