Heves megyei aprónyomtatványok 20/B
4 PNEUMATIC CYLINDERS Power Examining the power of cylinders you have to distinguish between — static power and — dynamic power. Power can be determined by formule below: Fstat — Ftheor Ffr Fc — ^ Ftheor — (0.85 . . . 0.95)Ftheor P AC Pc F = F — F dyn theor fr Fc = V • Ftheor = (0.50... 0.80) Ftheor an efficiency like factor — in case of static power it depend on the diameter of piston (e.g. D = 200 mm: T] = 0.95, D = 20 mm: T? = 0.85) — in case of dynamic power it depend on the velocity of piston (e.g. v = 0.1 m/s: 77 = 0.8, v = 1 m/s: 17 = 0.5) counterforce, F = 10pc • Ac [N] L surface area of counterside of the piston (cm2) counterpressure (bar) Friction force, Ffr [N] Theoretical force, F h = 10p • A [l\l] surface area of piston (cm2) supply pressure (bar) Effective power, Fstat, Fdyn [N] The effective power of cylinders is about — 85 ... 95 % of theoretical force in case of static power and — 50 ... 80 % of theoretical force in case of dynamic power because of affecting of frictional and counterforce. Piston rod force diagram Diameter of piston rod 100 1000 10000 Effective power, F [N]
