Concept explainers
Example 17-2 resulted in selection of a 10-in-wide A-3 polyamide flat belt. Show that the value of F1 restoring f 0.80 is
and compare the initial tensions.
Whether the value of
Explanation of Solution
Write the expression for tight side in belt.
Here, the centrifugal tension is
Write the expression for slack side in belt.
Write the expression for initial tension in belt.
Write the expression for coefficient of friction of belt material.
Now add and subtract
Conclusion:
Substitute
Substitute
Substitute
Substitute
Thus, the value of
Want to see more full solutions like this?
Chapter 17 Solutions
Shigley's Mechanical Engineering Design (McGraw-Hill Series in Mechanical Engineering)
- 3. Determine the principal dimensions of a cone faced with leather to transmit 30 kW at 750 rpm from an electric motor to an air compressor. Sketch a sectional front view of the clutch and provide the main dimensions on the sketch. Assume: semi-angle of the cone = 12 1/2°; f = 0.2; mean diameter of cone = 6 to 10d where d is the diameter of shaft; allowable normal pressure for leather and cast iron = 0.075 to 0.1 N/mm²; load factor = 1.75 and mean diameter to face width ratio = 6.arrow_forwardpleassssse solve question 7, staticsarrow_forwardA single disc clutch with both sides effective is required for a vehicle. The power for initial estimation of the clutch is 100 kW at 4000 rpm. Determine the radial dimensions (inner and outer radius) and the actuating force (W). Base the design on the uniform wear assumption. Assume maximum pressure (pmax) as 1.6 MN/m2 and ?2?1= 1√2where ‘r2’ and ‘r1’ represent inner and outer radius of the friction surface. Take µ = 0.35. Find also the minimum pressure (pmin).arrow_forward
- spring is to be inserted with an initial compression to produce a force equal to 125 N between the right-hand end of the lever and the stop. When the maximum force at A reaches to a value of 200 N, the end of the lever moves downward by 25 mm. assuming a spring index 8 determine the following parameters: 1. Spring rate 2. Size of the wire 3. Outside diameter of the spring 4. Number of active coils, and 5. Free length, assuming squared and ground ends Note: the allowable shear stress may be taken as 420 MPa, and G = 80 GPa. Hint: Ans. 0.33 N/mm: 3.4 mm; 27.2 mm; 77 mm - 200 mm - 200 mm Lever Stop -Springarrow_forwardConsider a pulley system shown below. The coordinate x is the displacement of G. Assume there is no slip between the cord and the pulley, and disk and the ground. What is the correct expression for the stretch in the spring? Select all that apply.arrow_forwardConsider the system shown below. Answer Questions 6-11 based on this figure. How many degrees-of-freedom does the system shown below has? The two pulleys have the identical mass, radius, and the moment of inertia. т, 1, R k т, 1, R Variables x: vertical position of the moving pulley 8: rotation of the moving pulley p: rotation of the fixed pulley m: pulley mass R: pulley radius I: mass moment of the pulley about its own center of mass. k: spring stiffness T: cable tension Assumptions 1. x = 0, 0 = 0, and o = 0 when the spring is undeformed. 2. The cables and springs have negligible mass. 3. There is no slip between the pulley and the cable. 4. Only two-dimensional planar motion is allowed.arrow_forward
- + Frictional Forces on Flat Belts When engineers design belt drives and band brakes, they engineer them to withstand the frictional forces that develop between the belts or bands and their contacting surfaces. These frictional forces lead to tensions on each side of the contacting surfaces that are unequal; the segment aligning with the motion of the belt or band has a greater tension. Figure B 0.500 m 0.200 m -0.400 m- A 3 of 3 0.300 m Part C mc= Block A has a mass of mA = 49.0 kg and rests on a flat surface. (Figure 3)The coefficient of static friction between the block and the surface is A = 0.300. The coefficient of static friction between the rope and the fixed peg B is 0.320. The width of the block is d = 0.250 m. Find the greatest mass, mc, that weight C can have such that block A does not move. Express your answer numerically in kilograms to three significant figures. ▸ View Available Hint(s) Submit Drouide Foodbook VAZO I vec ? 1 of 3 kg > Reviewarrow_forwardDetermine the principal dimensions of a cone clutch faced with leather to transmit 55 kW at 1100 r.p.m. from an electric motor to an air compressor. Sketch a sectional front view of the clutch and provide the main dimensions on the sketch. Assume : semi-angle of the cone = 15; μ = 0.2; mean diameter of cone = 6 to 10 d where d is the diameter of shaft; allowable normal pressure for leather and cast iron = 0.075 to 0.1 N/mm2; load factor = 1.75 and mean diameter to face width ratio = 6.arrow_forwardProblem 4. For the belt drive shown below calculate the contact angle 0, if: D %3D 100 mт; d 3 30 тm; C = 300 mm. D-d 20 sin V4c² - (D – d)²- -1 D-d sin 20 Oparrow_forward
- A wagon weighing 5100 Kg moving at a speed of 8 km/h has to be brought to rest. Springs made of wire diameter 25mm with a Dm of 250mm and with 24 turns are available. Find the number of springs required in buffer to stop the wagon at a compression of 180mm. b)A close coiled helical spring is made of diameter wire 25mm. The spring index is 8. Findthe number of turns required and maximum allowable load if the allowable shear stress is100 MPa and elongation is limited to 40mm. [G=80 GPaarrow_forwardB) Determine the effective stiffness of the system shown below , in terms of the displacement x . Activate Wi Go to Settings archarrow_forwardThe ratio of stress to bulk modulus for compression of the material. Select the correct response. Dilatation Modular ratio Bulk's ratio Deformation < Previousarrow_forward
- International Edition---engineering Mechanics: St...Mechanical EngineeringISBN:9781305501607Author:Andrew Pytel And Jaan KiusalaasPublisher:CENGAGE L