Ex 3: A double threaded power screw with ACME threads is used to raise a load of 300kN. The nominal diameter is 100mm and the pitch is 12mm. The coefficient of friction at the screw threads is 0.15. Neglecting collar friction, calculate 1- Torque required to raise the load. 2- Torque required to lower the load. 3- Efficiency of the screw.

Ex 3: A double threaded power screw with ACME threads is used to raise a load of 300kN. The nominal diameter is 100mm and the pitch is 12mm. The coefficient of friction at the screw threads is 0.15. Neglecting collar friction, calculate 1- Torque required to raise the load. 2- Torque required to lower the load. 3- Efficiency of the screw.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

(9) A single thread trapezoidal metric thread has a pitch of 4mm &has a mean diameter of 18mm. It is used as a translation screw in conjunction with the collar having an outside diameter of 37mm & inside diameter of 27mm. Find the required torque in N-m to raise a load of 400kg, if the coefficient of friction is 0.3 for both threads & the collar.
Problem: A double-threaded power screw with ISO metric trapezoidal threads is used to raise a load of 300 kN, The nominal diamter is 100 mm & the pitch is 12mm. The coefficient of friction at screw threads is 0.15. Neglect the collor friction. Q.45 Torque required to raise the load is
Question 3 A single square thread power screw is to raise a load of 50 KN. A screw thread of major diameter of 34 mm and a pitch of 6 mm is used. The coefficient of friction at the thread and collar are 0.15 and 0.1 respectively. If the collar frictional diameter is 100 mm and the screw turns at a speed of 1 rev/s. (Given dm = 31mm, 1 = 6mm, dc = 100mm). Find: (a) the power input to the screw. (b) the combined efficiency of the screw and collar.
A square thread power screw has pitch of 4-mm with double threads. Applicable data are threadand collar coefficient of friction equal to 0.08, collar diameter of 40-mm, and a load of 6.4-kNper screw and mean diameter of 30mmDetermine:a. Torques required to rotate the screw with” and “against” the load.b. Overall efficiency.
(b)Find the torque required to raise the load of 15kN and mean diameter of triple threaded screw being 46mm. Also gIven pitch = 8mm and coefficient of friction is 0.15
A double square thread power screw has a mean radius of 90 mm and pitch of 12 mm is used to lift a load of 90 kN. If the friction of screw Is 0.14 and collar torque Is 25% of input torque, find the input torque required.
QI: A double-threaded 30-mm power screw is 30 mm in diameter with a pitch of 6 mm. The coefficients of friction are 0.05 for the collar and 0.08 for the threads. The frictional diameter of the collar is 40 mm. if Tg=18 N.m: 1- Find the A vertical load on the screw, the torque used to lower the load and screw efficiency. 2- Compute all the stresses on the screw body that will cause by the load.
(5) A 2½-in square thread steel screw is used in a common jack screw. There are 2¼TPI. The body of the jack is made of cast iron. The coefficient of friction on the threads is 0.15. The thrust collar at the top has an inside diameter of 1½-in & the outside diameter of 3.0in. The coefficient for the collar is 0.25. The load to be lifted by the jack screw is 2 tons. Determine: (a) the efficiency of the screw only; (b) the efficiency of the screw & the thrust collar; (c) the pull necessary @ the end of a 2.0ft lever to operate this screw jack.
34 in 3. The following data apply to the C-clamp: a. The screw is ACME with ¾" Diameter b. Coefficient of thread friction = 0.12 c. Coefficient of collar friction = 0.23 d. Mean collar radius = 0.55 in. e. Max. clamping force = 1000 lb Determine: The tightening torque The operator force at the end of the handle (Note: Use table 8-3 to determine the screw pitch (p))
2- In the shown connection, the coefficient of friction is 0.05. Calculate the minimum allowable tightening torque to carry the load F=1000N. If high tensile bolt 9.8, calculate the design factor of safety. 30 mm 16 mm 16 mm 6 mm bolt M10x1.5 16 mm 16 mm + 6 mm F
(11) Find the power required to drive a power screw lifting a load of 40001b. A 2½-in double square thread with 2TPI. is to be used. The frictional radius of the collar is 2-in and the coefficients of friction are 0.l for the threads and 0.15 for the collar. The velocity of the nut is 10fpm .
A power screw having single start square threads of 25 mm nominal diameter and 5 mm pitch is acted upon by an axial load of 10 kN. The outer and inner diameters of screw collar are 50 mm and 20 mm respectively. The coefficient of thread friction and collar friction may be assumed as 0.2 and 0.15 respectively. The allowable thread bearing pressure is 5.8 N/mm², find: 1. The torque required to rotate the screw during raising and lowering the load. 2. The maximum shear stress in the screw. 3. The number of threads of nut in engagement with the screw.