A gear and shaft with nominal diameter of 34 mm are to be assembled with a medium drive fit (H7/s6). The gear has a hub, with an outside diameter of 45 mm, and an overall length of 50 mm. The shaft is made from AISI 1020 CD steel, and the gear is made from steel that has been through hardened to provide Su = 700 MPa and Sy = 600 MPa. a) Specify dimensions with tolerances for the shaft and gear bore to achieve the desired fit. b) Determine the minimum and maximum pressures that could be experienced at the interfaces with the specified tolerances. c) Determine the worst-case static factors of safety guarding against yielding at assembly for the shaft and the gear based on Von-Mises failure theory. d) Determine the maximum torque that the joint should be expected to transmit without slipping.

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?