Concept explainers
A 6-in-widc polyamide F-l flat belt is used to connect a 2-in-diameter pulley to drive a larger pulley with an angular velocity ratio of 0.5. The center-to-center distance is 9 ft. The angular speed of the small pulley is 1750 rev/min as it delivers 2 hp. The service is such that a service factor Ks of 1.25 is appropriate.
- (a) Find Fc, Fi, (F1)a,. and F2, assuming operation at the maximum tension limit.
- (b) Find Ha, nfs, and belt length.
- (c) Find the dip.
(a)
The value of
The value of
The value of
The value of
Answer to Problem 2P
The value of
The value of
The value of
The value of
Explanation of Solution
Refer the Table
Refer the Table 17-4, “Pulley correction factor
Write the expression for weight of the foot of belt.
Here, width of belt is
Write the expression for velocity ratio.
Here, the velocity of the driven pulley is
Write the expression for contact angle for smaller pulley.
Here, the center distance between pulley is
Write the expression for velocity of the driving pulley.
Here, diameter of the driving pulley is
Write the expression for centrifugal tension
Here, weight of the belt per
Write the expression for torque
Here, the power delivered is
Write the expression for actuating force on tight side of the belt.
Here, the width of the flat belt is
Write the expression for difference in tension in tight side and slack side.
Write the expression for tension in slack side of belt.
Write the expression for initial tension in belt.
Conclusion:
Substitute
Substitute
Substitute
Substitute
Substitute
Thus, the value of
Substitute
Substitute
Thus, the value of
Substitute
Substitute
Thus, the value of
Substitute
Thus, the value of
(b)
The value of
The value of
The belt length.
Answer to Problem 2P
The value of
The value of
The belt length is
Explanation of Solution
Write the expression for the transmitted horse power.
Here, the velocity of the driving pulley is
Write the expression for factor of the safety.
Here, the transmitted horse power is
Write the expression for contact angle for bigger pulley.
Here, the center distance between pulley is
Write the expression for the length of the belt.
Conclusion:
Substitute
Thus, the value of
Substitute
Thus, the value of
Substitute
Substitute
Thus, the belt length is
(c)
The dip of the belt.
Answer to Problem 2P
The belt dip is
Explanation of Solution
Write the expression for belt dip.
Here, the center distance between pulley is
Conclusion:
Substitute
Thus, the belt dip is
Want to see more full solutions like this?
Chapter 17 Solutions
Connect 1-semester Access Card For Shigley's Mechanical Engineering Design
- power (N)=9.9kw Input speed (n1)=2350rpm Distance between centers (a)=168mm Total distance between Ave B bearings=440mm module(m)=3mm question 3 Calculate the power on the output shaft since there is 3% loss in gears in gearboxes, rolling bearings in support bearings (2% loss in a pair of bearings) and sealing element spring seal (4% loss in a pair of sealing elements).arrow_forwardTwo pulleys, one 650 mm diameter and the other 400 mm diameter, on parallel shafts 1.5 m apart are connected by a flat belt. Find the length of the belt required and the angle of contact between the belt and each pulley. What power can be transmitted by the belt when the larger pulley rotates at 1200 rev/min, if the maximum permissible tension in the belt is 10 kN, and the coefficient of friction between the belt and pulley is 0.05? dont write handwritten solution.arrow_forwardPower is transmitted between two pulleys mounted on the parallel shafts rotating in the opposite direction. The pulleys are separated apart at a distance of 1950mm having 0.45m and 0.2m diameter respectively. What power can be transmitted by the belt when the larger pulley rotates at 200 rev/min, if the maximum permissible tension on the tight side of the belt is 1000 N, and the value of µ between the belt and pulley is 0.25. Design the length of the belt required and the angle of contact between the belt and each pulley.arrow_forward
- Problem: A pump is driven by an electric motor through an open type flat belt drive. Determine the belt specificationsfor the following data.Motor pulley diameter= 400 mmPump pulley diameter = 800 mmCoefficient of friction for motor pulley = 0.30Coefficient of friction for pump pulley = 0.35Center distance between the pulleys=2000 mmRotational speed of the motor=2000 rpmPower transmission = 40kWdensity of belt material = 1000 kg/m3 width of the belt=240mmthickness of the belt = 5mmarrow_forwardA1. A flat belt drive for speed reduction has pulley diameters of 200 mm and 380 mm. Themaximum belt tension is not to exceed 620 N and it is required to transmit 1·8 kW at anoutput speed of 360 rev/min. Determine:(a) The input torque. (b) The belt speed. (c) The limiting slack side tension. (d) The initial tension at which the belt should be set.arrow_forwardA pulley 610 mm diameter is driven at 300 revs/min by a belt, the tensions in the tight and slack sides of the belt being 670 N and 270 N. Find the power transmitted.arrow_forward
- The agricultural machine is powered by an electric motor through a flat beltsystem. The machine requires 6 flat belts and 40 kW power to operate at aspeed of 350 rpm. The pulley diameter of the machine is 650 mm and the pulleyof the electric motor is 330 mm. The centre distance between the pulleys is1100 mm. The belt speed is not to exceed 30 m/s. Calculate the tensions in thebelt.arrow_forwardA mini motorcycle is driven by a combustion engine with mechanical transmission. The 12Hp motor spins at a speed of 1150 rpm. The motorcycle runs at a linear speed of 45 km/h on 12-inch wheels. Preliminary center to center distance is 13”. This type of motorcycle requires two strands (conical double sleeve assembly) and is subjected to hard shocks. a) Calculate the effective power.b) Choice of chain and sprocket. (Standard part number, see catalog)c) Calculate the speed ratio. https://pdf.directindustry.com/pdf/martin-sprocket-gear/general-catalog/9091-246439.htmlarrow_forwardA 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_forward
- Flat Belts. Two shafts 10 ft apart, with axes in the same horizontal plane, are to be connected with a flat belt in which the driving pulley, powered by an electrical motor with a 25 hp rating at 900 rev/min, drives the second shaft at half its angular speed. The driven shaft drives uniform (smooth) machinery loads. Select a flat belt.arrow_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_forward3.A chain drive using bush roller chain transmits 5.6 kW of power. The driving shaft on an electric motor runs at 1440 r.p.m. and velocity ratio is 5. The centre distance of the drive is restricted to 550 ± 2% mm and allowable pressure on the pivot joint is not to exceed 10 N/mm2. The drive is required to operate continuously with periodic lubrication and driven machine is such that load can be regarded as fairly constant with jerk and impact. Design the chain drive by calculating leading dimensions, number of teeth on the sprocket and specify the breaking strength of the chain. Assume a factor ofarrow_forward
- International Edition---engineering Mechanics: St...Mechanical EngineeringISBN:9781305501607Author:Andrew Pytel And Jaan KiusalaasPublisher:CENGAGE L