13. A skip for a mine shaft weighs 2000 lb and is to lift a maximum load of 3000 lb from a depth of 1000 ft. The maximum speed of 20 fps is attained in 5 seconds. a. What sizes of 6x19, IPS rope and sheave should be used for indefinite life and N = 1.3 on the basis of fatigue? b. What is the design factor on the static basis? c. What sizes of rope and sheave are required if the number of cycles (bending and unbending) in the desired life is 200,000?What is the corresponding static design factor?

13. A skip for a mine shaft weighs 2000 lb and is to lift a maximum load of 3000 lb from a depth of 1000 ft. The maximum speed of 20 fps is attained in 5 seconds. a. What sizes of 6x19, IPS rope and sheave should be used for indefinite life and N = 1.3 on the basis of fatigue? b. What is the design factor on the static basis? c. What sizes of rope and sheave are required if the number of cycles (bending and unbending) in the desired life is 200,000?What is the corresponding static design factor?

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

3) A double screw (Acme thread angle o = 14.5) mechanism is designed to lift a load of 18,000 lb in such a way that screw is loaded in tension. Use of Safe Factor of safety of 3.2. Select a suitable screw from data table provided in class notes for tensile load and shear load. Limiting tensile and shear stresses are 10,000 psi and 5,500 psi, respectively. Required thickness of Yoke which functions as a nut. It is desired to raise the hatch a total of 30.0 inches in 15 seconds. Use coefficient of friction f= 0.15. List necessary assumptions. Sketch and Label a schematic diagram. Determine a. Nominal major diameter of screw (D) b. Threads per Inch of selected thread (n) c. Thickness of Yoke (h) d. Lead angle (2) e. Torque required to raise the load (Tup) f. Torque required to lower the load (Tdown) g. Efficiency of the screw h. RPM required to operate each screw i. Compute the Total Power required to operate the mechanism.
the shaft and Bols bolts. [Ans. 300 mm; 56 mm] 11. Design a bushed-pin type flexible coupling for connecting a motor shaft to a pump shaft for the following service conditions: Power to be transmitted = 40 kW; speed of the motor shaft= 1000 r.p.m. ; diameter of the motor shaft = 50 mm ; diameter of the pump shaft = 45 mm. The bearing pressure in the rubber bush and allowable stress in the pins are to be limited to 0.45 N/mm2 and 25 MPa respectively. [Ans. d, = 20 mm; n 6; d, = 40 mm; 1 152 mm] :1.1
A winch drum of diameter 161 mm turning at 12pm lifts a load of 7.5kN. What is the winch output power?
4) An electric motor purchased by your employer surprisingly arrived without a keyway in the shaft. The motor has power rating of 7.5kW & 1,800rpm & has a shaft of 17mm. It will be used to drive a centrifugal pump using cast iron sheave. Design the square key to be used in the assembly based on maximum bearing & shearing stresses of 580MPa & 370MPa, respectively, and factor of safety of 5.
Q1: Design and draw a cast iron flange coupling for a mild steel shaft transmitting 80 kW at 220 rpm with the following specifications: Allowable shear stress in the shaft = 400 MPa Permissible angle of twist < 1° in a length of 20 diameters Allowable shear stress in the coupling bolts 30 MPa Rigidity modulus of shaft materials = 85 GPa Allowable shear stress for hub material = 15 MPa You may adopt, width of key = 25 mm, thickness of key = 14 mm You may also consider that the shaft and key are made of the same material. Four number of bolts are to be used in the coupling. Find out the diameter of the shaft required and main dimensions of the flanges and the key. Adopt suitable dimensions. Draw a neat sketch for the flange coupling with the designed dimensions.
Design and draw a neat sketch of a cast iron protective type flange coupling to transmit “P” kW at “N” rpm. from a turbine generating n electric motor to a compressor. The service factor may be assumed as 1.35. The following permissible stress may be used: Shear stress for shaft, bolt and key material = 40 MPaCrushing stress for bolt and key = 80 MPaShear stress for cast iron = 8 MpaSpeed N in Rpm = 250Power P in kN = 21
Q1) A V-belt drive consists of three V-belts in parallel on grooved pulleys of the same size. The angle of groove is 30° and the coefficient of friction 0.12. The cross-sectional area of each belt is 800 mm² and the permissible safe stress in the material is 3 MPa. Calculate the power that can be transmitted between two pulleys 400 mm in diameter rotating at 960 rpm.
Please answer in this format. Sketch: Given: Required: Solution: (Please answer in detailed (step by step). Indicate labels on what you are doing/performing, for example what formula is used) A torque To is transmitted between two flanged shafts by means of four 20-mm bolts. diameter of the bolt circle is 2=150mm. If the allowable shear stress in the bolts is 90 Mpa, what is the maximum permissible torque? Disregard friction between between flanges. The To
Problem 1: The pin in a Box-Pin coupling is acted upon by a force (F), that varies as random variable due to misalignment as (2, 0.08) kN. The load act at a distance (1) that varies as (25 ± 3) mm. The diameter of the pin (D) is 18 mm. The fillet radius at the pin shoulder is about 1.5 mm. The stress concentration factor due to fatique in bending is thus a random variable kb that could vary from 1.3 to 1.5. The pin is made of steel AISI 4340 with mean endurance strength in bending of 400 MPa, and a standard deviation of 25 MPa. Determine the pin diameter (d), if one pin in every 10000 may be permitted to fail. R1.6 O L Problem (1)
10. A simply supported shaft between bearings camies a steady load of 10 kN at the centre. The length of shaft between bearings is 450 mm. Neglecting the effect of stress concentration, find the minimum diameter of shaft. Given that Endurance limit = 600 MPa; surface finish factor = 0.87; size factor = 0.85; and factor of safety = 1.6. [Ans. 35 mm]
Provide step-by-step solution with complete given and formula to this problem. Draw sketch also. A mine hoist is to carry a cage loaded with ore at a total load of 8 tons. The depthof mine shaft is 328 ft. A 6 x 19 IPS wire rope with rope diameter of 1.75 in is to beuse with sheave diameter of 39 in. The cage loaded is to start from rest and will attaina maximum velocity of 525 fpm in 10 seconds. Find the total load of the rope. A. 12,086 lbs B. 14,086 lbs C. 16,086 D. 18, 086 lbs
A bolt with a square threaded screw has mean diameter of 25 mm and a pitch of 3 mm. It carries an axial thrust of 10 kN on the bolt head of 25 mm mean radius. If u = 0.12, find the force required at the end of a spanner 450 mm long, in tightening up the bolt. 3. [Ans. 110.8 N] A turn buckle with right and left hand threads is used to counle twvo railway coaches The threads