The world’s Largest Sharp Brain Virtual Experts Marketplace Just a click Away
Levels Tought:
Elementary,Middle School,High School,College,University,PHD
| Teaching Since: | May 2017 |
| Last Sign in: | 433 Weeks Ago |
| Questions Answered: | 66690 |
| Tutorials Posted: | 66688 |
MCS,PHD
Argosy University/ Phoniex University/
Nov-2005 - Oct-2011
Professor
Phoniex University
Oct-2001 - Nov-2016
A double-threaded Acme stub screw of 2-in. major diameter is used in a jack having a plain thrust collar of 2.75-in. mean diameter. Coefficients of running friction are estimated as 0.10 for the collar and 0.11 for the screw.
(a) Determine the pitch, lead, thread depth, mean pitch diameter, and helix angle of the screw.
(b) Estimate the starting torque for raising and for lowering a 3500-lb load.
(c) If the screw is lifting a 3500-lb load at the rate of 4 ft/min, what is the screw rpm? What is the efficiency of the jack under this steady-state condition?
(d) Would the screw overhaul if a ball thrust bearing (of negligible friction) were used in place of the plain thrust collar?
Hel-----------lo -----------Sir-----------/Ma-----------dam-----------Tha-----------nk -----------You----------- fo-----------r u-----------sin-----------g o-----------ur -----------web-----------sit-----------e a-----------nd -----------acq-----------uis-----------iti-----------on -----------of -----------my -----------pos-----------ted----------- so-----------lut-----------ion-----------.Pl-----------eas-----------e p-----------ing----------- me----------- on-----------cha-----------t I----------- am----------- on-----------lin-----------e o-----------r i-----------nbo-----------x m-----------e a----------- me-----------ssa-----------ge -----------I w-----------ill----------- be-----------