Dynamic safety

  1. A paper machine processes rolls of paper having a density of 984 kg/m3. The paper roll is 1.50-m outside dia (OD) X 0.22-m inside dia (ID) X 3.23 m long and is on a simply supported, hollow, steel shaft with Sut = 400 MPa. Design a 2.5:1 reduction helical gearset to drive this roll shaft to obtain a minimum dynamic safety factor of 2 for a 10-year life if the shaft OD is 0.22 m and the roll turns at 50 rpm with 1.2 hp absorbed.
  2. A 2-start wormset has d = 50 mm, px = 10 mm, mG = 22:1. Find the lead, lead angle, worm-gear diameter, and center distance. Will it self-lock? The input speed is 2 200 rpm.


Approximately 250 words