Design an infinite-life helical coil extension spring with full end loops and generous loop-bend radii for a minimum load Fmin of 8 lbf and a maximum load Fmax of 16 lbf, with an accompanying stretch of ¼ in. The spring is for a food-service equipment and must be stainless steel. The outside diameter of the coil cannot exceed 1 in, and the free length cannot exceed 2.5 in. Using a fatigue design factor of nf = 2, complete the design. Use the Gerber criterion with Table 10-8.

Design an infinite-life helical coil extension spring with full end loops and generous loop-bend radii for a minimum load Fmin of 8 lbf and a maximum load Fmax of 16 lbf, with an accompanying stretch of ¼ in. The spring is for a food-service equipment and must be stainless steel. The outside diameter of the coil cannot exceed 1 in, and the free length cannot exceed 2.5 in. Using a fatigue design factor of nf = 2, complete the design. Use the Gerber criterion with Table 10-8.

Mechanics of Materials (MindTap Course List)

9th Edition

ISBN:9781337093347

Author:Barry J. Goodno, James M. Gere

Publisher:Barry J. Goodno, James M. Gere

Chapter2: Axially Loaded Members

Section: Chapter Questions

Problem 2.2.11P: A small lab scale has a rigid L-shaped frame ABC consisting of a horizontal arm AB (length b = 10...

See similar textbooks

Similar questions

(9) A Mercedes Benz gas engine valve spring should not exceed to a cylindrical space of 1¾-in in diameter. The spring index is 6.0 & the maximum load it will have to sustain is l00lb with corresponding deflection of ½-in. The spring is subjected to repeated loading & fatigue must be considered, a low working stress of 40,110psi will be used. Determine: (a) the diameter of wire based on commercial sizes; (b) the number of coils.
A bushed pin type flexible coupling is used to transmit 10 kW power at 720 rpm. The design torque is 150% of rated torque. The keys have square cross-section. The permissible stresses are: For shaft and key material, τ = 66.67 N/mm2 , σc = 200 N/mm2 ; For pin material, τ = 35 N/mm2 , σt = 133 N/mm2 ; For flange material τ = 16.67 N/mm2 . The permissible bearing pressure for rubber bushes is 1 N/mm2. The number of bushes is 4. Design the bushed pin flexible coupling. Explain Axle, Spindle, Counter shaft and line-shaft with their examples .
A bushed pin type flexible coupling is used to transmit 10 kW power at 720 rpm. The design torque is 150% of rated torque. The keys have square cross-section. The permissible stresses are: For shaft and key material, τ = 66.67 N/mm2, σc = 200 N/mm2; For pin material, τ = 35 N/mm2, σt = 133 N/mm2; For flange material τ = 16.67 N/mm2. The permissible bearing pressure for rubber bushes is 1 N/mm2. The number of bushes is 4. Design the bushed pin flexible coupling.
a helical compression spring with squared and ground ends is made of shot-peened astm a232 spring wire with presetting(G=79 GPa) . It is used to control a cyclic dynamic load that varies between 562 and 0 N. if a saftey factor of 1.12 is used, determine the allowable shear stress for a design cinsideration of infinite fatigue life
A helical compression spring is 1o exert a force of 8.0 Ib when compressed 1o a length of 1.75 in. At a length of 1.25 in, the force must be 12.0 Ib. The spring will be installed in a machine that cycles slowly. and approximately 200 000 cycles total are expected. The tem- perature will not exceed 200°F. The spring will be installed in a hole having a diameter of 0.75 in. For this application. specify a suitable material, wire diameter. mean diameter. OD. ID. free length, solid length. number of coils, and type of end condition. Check the stress at the maximum operating load and at the solid length condition. The first of two solution procedures will be shown. The numbered steps can be used as a guide for future problems and as a Kind of algorithm for the spreadsheet approach that follows the manual solution.
Q) A helical compression spring of a mechanism is subjected to Pas =120 N 19ad cycle. The diameter if the wire is 3 mm, with a spring index of € = 7 P, =4N and .The spring is made of oil-hardened and tempered steel, with”« ~ L0t dm Determine the factor of safety in fatigue loading.
Starting with a spring index of C = 10, design a compression coil spring of 302 stainless wire with squared ends. The spring deflects 50 mm when a force of 90 N is applied and closes to solid when ys is 60 mm. At closure, use a design factor of 1.2 guarding against yielding. Select the smallest diameter wire where wire diameters are available in 0.2-mm increments between 0.2 and 3.2 mm. For the design, specify the wire diameter, the inside and outside diameters of the coil, the spring rate, the total number of coils, the free length of the spring, the final factor of safety, and stability conditions.
A mechanism used in printing machinery consists of a tension spring assembled with a preload of 40 N. The mean diameter of the coilis 32 mm with a spring index of 8. The spring has 18 active coils. The spring wire is hard drawn and oil tempered having the following material properties: a.Design shear stress = 700 MPb b. .Modulus of rigidity = 80 kN/mm2 Identify (a) the initial torsional shear stress in the wire, (b) the spring rate, and (c) the force to cause the body of the spring to reach its yield strength.
(2) A coil spring is to be used for the front suspension of a car. The spring is to have a rate of 400lb/in, an inside diameter of 4.0-in, & a free length of 14⅛-in, with squared & ground ends. The material is to be oil-tempered chrome-vanadium steel. Recommend the rod diameter & the number of coils for a design load of 1,500lb.
A helical compression spring has a scale of 500 lb/in., an outside diameter of 2.75 in, a free length of 8 inches and with squared and ground ends. The load is 1,000 lbs and the working stress on the wire material is 65000 psi. If the Wahl factor of 1.25 is to be used, calculate the following: A. The standard wire diameter B. The number of active coil if G = 10 800 000 psi C. The solid height D. The stress at solid height
Design a helical compression spring to be used in a cam and follower mechanism made of oil tempered carbon steel, is subjected to a load which varies from 416 N to 950 N. The spring index is 6.7 and the design factor of safety is 1.25. If the yield stress in shear is 770 MPa and endurance stress in shear is 350 MPa,find: 1. Size of the spring wire, 2. Diameters of the spring, 3. Number of turns of the spring, and 4. Free length of the spring. The compression of the spring at the maximum load is 30 mm. The modulus of rigidity for the spring material may be taken as 80 kN/mm2.
A helical compression spring is to be used for a maximum load of 1.5 kN using the spring index of 8. The maximum permissible shear stress for the spring wire is 400 MPa. Which of the following is the wire diameter of the spring to be used?