FLENDER gear units - DS TECH

© Siemens AG 2011Selection of the gear unitsGuidelines for selection■ OverviewKnown criteria for the calculation examplePrime mover:• Electric motor, 6-pole:• Motor speed:• Max. starting torque:P 1 = 55 kWn 1 = 1000 rpmT A = 1332.5 NmDriven machine:• Section mill:P 2 = 45 kW• Speed:n 2 = 32 rpm• Duty:24 h/day• Starts per hour: 15• Operating cycle per hour: E D = 40 %• Ambient temperature: t U = 50 °C• Installation in a large hallGear unit design:• Planetary gear unit• Mounting position:• Output shaft d 2 :• Direction of rotation ofoutput shaft d 2 :horizontalHollow shaft with shrink diskcounterclockwise, whenviewing the shaft end faceThe influence of additional forces on the shaft ends mustbe taken into account.Required:•Type of gear unit•Gear unit size1. Determination of gear unit type and size1.1 Find the transmission ration 1i s = =n 21000 rpm32 rpmCalculation example1.2 Determine the nominal power rating of the gear unitFrom table, see Page 3/8 (nominal power rating P 2N ) gear unitsize FLENDER SIP 45 with P 2N = 127 kW selected.1.3 Check the maximum loadingNo load stage exceeds the permissible maximum loading.1.4 Check for over dimensioning= 31.25 → i N = 30 selectedP 2N ≥ P 2 f 1 f 2 = 45 kW 2.5 1 = 112.5 kWP max = 45 kW < 1.5127 kW = 190.5 kW3.33 P 2 ≥ P 2N 3.33 45 kW = 149.85 kW > P 2N3It is not necessary to consult Siemens.1.5 Check the starting torque1275 Newton, local 15Boucherville, Qc,Canada, J4B 5H2T A n 1P 2N ≥ f 3 =9550P 2N = 127 kW < 175.8 kW1332.5 Nm 1000 rpm9550It is necessary to limit the motor torque on starting.1.26 = 175.8 kW1.6 Check the thermal capacity P GCheck whether P G ≥ P 2P G = P GA f 4 = 42 kW 0.74 = 31.08 kWDue to insufficient thermal capacity, another gear unit size, in thiscase FLENDER SIP 55, must be selected with:P G = 63 kW:P G = P GA f 4 = 63 kW 0.74 = 46.62 kWThere will then be no need to limit the starting torque of the motor,because the following applies for the selected gear unit size:P 2N = 236 kW > 175.8 kW(450) 655-7447info@pt-dstech.comwww.dstech.caSiemens MD 31.1 · 20113/5