FLENDER Standard Couplings Coupling Preselection and Options © Siemens AG 2015 Selection of the coupling size ■ Selection and ordering data The torque load of the coupling must be determined from the output of the driven machine and the coupling speed. Examples of torque characteristic of driving machines: • uniform: Electric motors with soft starting, steam turbines • uniform with moderate shock loads: Electric motors without soft starting, hydraulic motors, gas and water turbines • non uniform:
Internal-combustion engines Rated coupling load T N = 9550 · P N / n N ( T N in Nm; P N in kW; n N in rpm) The rated coupling load obtained in this way must be multiplied by factors and compared with the rated coupling torque. An ideal but expensive method is to measure the torque character- istic on the coupling. For this, Siemens offers special adapters fitted with torque measuring devices. 3 Examples of torque characteristic in driven machines: • uniform: Generators, centrifugal pumps for light fluids • uniform with moderate shock loads: Centrifugal pumps for viscous fluids, elevators, machine tool drives, centrifuges, extruders, blowers, crane drives • non uniform:
Excavators, kneaders, conveyor systems, presses, mills • very rough: Crushers, excavators, shredders, iron/smelting machinery The rated coupling torque T KN is the torque which can be trans- mitted by the coupling over an appropriate period of use if the load is applied to the coupling purely statically at room temper- ature. Application factors are to express the deviation of the real cou- pling load from the "ideal" load condition. Coupling load in continuous operation The operating principles of the driving and driven machines are divided into categories and the application factor FB derived from these in accordance with DIN 3990-1.
NR = natural rubber, natural-synthetic rubber mixture NBR = nitril-butadiene-rubber (Perbunan) HNBR = hydrated acrylonitrile butadiene rubber CR = chloroprene rubber (FRAS fire-resistant and anti-static) VMQ = silicone TPU = polyurethane In the case of ARPEX and ZAPEX coupling types, no temper- ature factor (FT = 1.0) need be taken into account. Coupling size T KN ≥ T N · FB · FT 1) The N-EUPEX coupling is not suitable for shock loads when used at low temperatures.
3/6 Siemens MD 10.1 · 2015 Application factor FB Torque characteristic of the driven machine Torque characteristic of the driving machine uniform uniform with moderate shock loads non uniform very rough uniform 1.0 1.25 1.5 1.75 uniform with moderate shock loads 1.25 1.5 1.75 2.0 non uniform 1.5 1.75 2.0 2.5 Temperature factor FT Temperature Ta on the coupling Coupling Elastomer material Low temperature °C under -30 °C -30 °C to 50 °C to 60 °C to 70 °C to 80 °C to 90 °C to 100 °C to 110 °C to 120 °C N-EUPEX NBR -30 – 1.0 1.0 1.0 1.0 – – – – N-EUPEX NR -50 1.11) 1.0 – – – – – – – N-EUPEX HNBR -30 – 1.0 1.0 1.0 1.0 1.25 1.25 – – N-EUPEX DS NBR -30 – 1.0 1.0 1.0 1.0 – – – – RUPEX NBR -30 – 1.0 1.0 1.0 1.0 – – – – RUPEX NR -50 1.1 1.0 1.0 – – – – – – RUPEX HNBR -30 – 1.0 1.0 1.0 1.0 1.25 1.25 – – N-BIPEX TPU -50 1.0 1.0 1.0 1.0 1.0 1.0 1.0 – – ELPEX NR -40 1.1 1.0 1.25 1.40 1.60 – – – – ELPEX-B NR -50 1.1 1.0 – – – – – – – ELPEX-B CR -15 – 1.0 1.0 1.0 – – – – – ELPEX-S SN, NN, WN NR -40 1.1 1.0 1.25 1.40 1.60 – – – – ELPEX-S NX VMQ -40 1.1 1.0 1.0 1.0 1.0 1.1 1.25 1.4 1.6