Engineering, 11.04.2020 04:03 chris159128

A double threaded Acme stub screw of 2-inch major diameter is used in a jack having a plain thrust collar of 2.5

inch 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 5000 lb load.

(c) If the screw is lifting a 5000 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.

Answers: 1

Show answers

Another question on Engineering

Engineering, 04.07.2019 18:10

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?

Answers: 3

Answer

Engineering, 04.07.2019 18:10

Items are similar to the free issue items, but their access is limited. (clo5) a)-bin stock items free issue b)-bin stock controlled issue c)-critical or insurance spares d)-rebuildable spares e)-consumables

Answers: 1

Answer

Engineering, 04.07.2019 18:10

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.

Answers: 3

Answer

Engineering, 04.07.2019 18:20

Wiy doeres rere okhn a pump whon working betwon the same pressure range?

Answers: 2

Answer

You know the right answer?

A double threaded Acme stub screw of 2-inch major diameter is used in a jack having a plain thrust c...

Questions