{ "metadata": { "name": "chapter 11.ipynb" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 11:Belts,Ropes And Chain Drives" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.1,Page No.386" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "N1=200 #r.p.m\n", "d1=51 #cm #Dia. of engine\n", "d2=30 #cm #Dia. of driven shaft\n", "\n", "#Calculations\n", "\n", "#Speed of driven shaft\n", "N2=d1*d2**-1*N1 #r.p.m\n", "\n", "#Result\n", "print\"Speed of driven shaft is\",round(N2,2),\"r.p.m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Speed of driven shaft is 340.0 r.p.m\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.2,Page No.386" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "t=1 #cm #thickness\n", "N1=200 #r.p.m\n", "d1=51 #cm\n", "d2=30 #cm\n", "\n", "#Calculations\n", "\n", "#Speed of shaft\n", "N2=(d1+t)*(d2+t)**-1*N1 #r.p.m\n", "\n", "#Result\n", "print\"speed of shaft is\",round(N2,2),\"r.p.m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "speed of shaft is 335.48 r.p.m\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.3,Page No.388" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "N1=200 #r.p.m\n", "N2=300\n", "d1=60 #cm\n", "t=0.5 #cm\n", "s=4 #%\n", "\n", "#Calculations\n", "\n", "#Diameter of pulley\n", "d2=N1*N2**-1*d1 #cm\n", "\n", "#Taking belt thickness\n", "d2_2=(d1+t)*N1*N2**-1-t\n", "\n", "#Also considering slip\n", "d2_3=(d1+t)*N1*N2**-1*(1-s*100**-1)-t #cm\n", "\n", "#Result\n", "print\"Diameter of belt is:Neglecting belt thickness\",round(d2,2),\"cm\"\n", "print\" :Belt thickness only\",round(d2_2,2),\"cm\"\n", "print\" :Considering belt thickness and slip\",round(d2_3,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Diameter of belt is:Neglecting belt thickness 40.0 cm\n", " :Belt thickness only 39.83 cm\n", " :Considering belt thickness and slip 38.22 cm\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.4,Page No.389" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "d1=1 #m #dia. of driver pulley\n", "N1=200 #r.p.m #Speed of driver pulley\n", "d2=2.5 #m #Dia. of driven pulley\n", "f1=1.44 #N/mm**2 #strress\n", "f2=0.49 #N/mm**2 \n", "E=100 #N/mm**2 #Young's Modulus\n", "\n", "#Calculations\n", "\n", "#Speed of driven pulley\n", "N2=d1*d2**-1*(E+round((f2)**0.5,2))*(E+round((f1)**0.5,2))**-1*N1\n", "\n", "#Speed if creep is neglected\n", "N2_2=d1*d2**-1*N1 #r.p.m\n", "\n", "#Speed lost by driven pulley due to creep\n", "N=N2_2-N2\n", "\n", "#Result\n", "print\"speed Lost by driven pulley due to creep is\",round(N,3),\"r.p.m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "speed Lost by driven pulley due to creep is 0.395 r.p.m\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.5,Page No.390" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "d1=1 #m #Diameter\n", "N1=200 #r.p.m\n", "d2=2.5 #m\n", "b=500 #mm #width\n", "t=10 #mm #thickness\n", "E=100 #N/mm**2\n", "\n", "#Calculations\n", "\n", "#Area\n", "A=b*t #mm**2\n", "\n", "#Tension on tight side\n", "T1=10*b\n", "\n", "#Tension on slack side\n", "T2=4*b #N\n", "\n", "#Stress on tight side\n", "f1=T1*A**-1 #N/mm**2\n", "\n", "#Stress on slack side\n", "f2=T2*A**-1 #N/mm**2\n", "\n", "#Speed of driven pulley\n", "N2=d1*d2**-1*(E+(f2)**0.5)*(E+(f1)**0.5)**-1*N1\n", "\n", "#Speed if creep is neglected\n", "N2_2=d1*d2**-1*N1 #r.p.m\n", "\n", "#Speed lost by driven pulley due to creep\n", "N=N2_2-N2\n", "\n", "#Result\n", "print\"speed Lost by driven pulley due to creep is\",round(N,2),\"r.p.m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "speed Lost by driven pulley due to creep is 0.29 r.p.m\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.6,Page No.392" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "d1=80 #cm #Diameter of driver pulley on engine\n", "d2=40 #cm #Dia. of follower pulley on line shaft\n", "d3=100 #cm #Dia. of driver pulley on line shaft\n", "d4=20 #cm #Dia. of follower pulley on dynamo shaft\n", "s1=s2=2.5 \n", "\n", "#Calculations\n", "\n", "#Speed of dynamo shaft\n", "\n", "#When there is no slip\n", "N4=d1*d3*(d2*d4)**-1*N1 #r.p.m\n", "\n", "##When there is slip of 2.5 %\n", "N4_2=N1*d1*d3*(d2*d4)**-1*(1-s1*100**-1)*(1-s2*100**-1)\n", "\n", "#Result\n", "print\"Speed of the dynamo when:When there is no slip\",round(N4,2),\"r.p.m\"\n", "print\" :When there is slip of 2.5 %\",round(N4_2,2),\"r.p.m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Speed of the dynamo when:When there is no slip 2000.0 r.p.m\n", " :When there is slip of 2.5 % 1901.25 r.p.m\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.7,Page No.397" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "x=600 #cm #Distance between shafts\n", "r1=30 #cm #radius\n", "r2=20 #cm \n", "\n", "#Calculations\n", "\n", "#If belt is open \n", "L1=pi*(r1+r2)+(r1-r2)**2*x**-3+2*x #cm \n", "\n", "#If belt is crossed\n", "L2=pi*(r1+r2)+(r1+r2)**2*x**-1+2*x #cm\n", "\n", "#Result\n", "print\"If belt is open Length is\",round(L1,2),\"cm\"\n", "print\"If belt is crossed length is\",round(L2,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "If belt is open Length is 1357.08 cm\n", "If belt is crossed length is 1361.25 cm\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.8,Page No.397" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "#speed of shafts\n", "N1=N3=N5=160 #r.p.m\n", "N2=60 #r.p.m\n", "N4=80 #r.p.m\n", "N6=100 #r.p.m\n", "x=180 #cm #Distance between shafts\n", "r1=15 #cm #Radius of smallest pulley\n", "\n", "#Calculations\n", "\n", "#Radii of pulley 2\n", "r2=r1*N1*N2**-1 #cm\n", "\n", "#using same above equation for radii of pulley 3 we get and further simplifying we get\n", "#r4=2*r3 ..................1\n", "\n", "#but for crossed belt equation is\n", "#r1+r2=r3+r4=r5+r6 .................2\n", "#After further simplifying we get\n", "r3=(r1+r2)*3**-1 #cm\n", "r4=2*r3 #cm\n", "\n", "#Using same above equation and further simplifying we get\n", "#r6=1.6*r5 ...............3\n", "\n", "#sub value of r6 in equation we get\n", "r5=(r1+r2)*2.6**-1 #cm\n", "r6=1.6*r5 #cm\n", "\n", "#Length of open belt\n", "L=pi*(r1+r2)+(r1-r2)**2*x**-1+2*x #cm\n", "\n", "#For pulley 3 and 4 equation is\n", "#L=pi*(r3+r4)+(r3-r4)**2*x**-1+2*x\n", "#sub value in above equation we get an equation as\n", "#r3**2+1696.5*r3-31710.6=0\n", "a=1\n", "b=1696.5\n", "c=-31710.6\n", "\n", "X=b**2-4*a*c\n", "\n", "r3_2=(-b+X**0.5)*2**-1 #cm\n", "r4_2=2*r3_2 #cm\n", "\n", "#Sim for r5 & r6 \n", "\n", "#L=pi*(r6+r5)+(r6-r5)**2*x**-1+2*x\n", "#sub value in above equation we get an equation as\n", "#r5**2+4084*r5-88085=0\n", "a=1\n", "b=4084\n", "c=-88085\n", "\n", "X=b**2-4*a*c\n", "\n", "r5_2=(-b+X**0.5)*2**-1 #cm\n", "r6_2=1.6*r5_2 #cm\n", "\n", "#Result\n", "print\"Radii of two stepped pulleys is:For crossed belt:r3\",round(r3,2),\"cm\"\n", "print\" :r4\",round(r4,2),\"cm\"\n", "print\" :r5\",round(r5,2),\"cm\"\n", "print\" :r6\",round(r6,2),\"cm\"\n", "print\"Radii of two stepped pulleys is:For open belt:r3_2\",round(r3_2,2),\"cm\"\n", "print\" :r4_2\",round(r4_2,2),\"cm\"\n", "print\" :r5_2\",round(r5_2,2),\"cm\"\n", "print\" :r6_2\",round(r6_2,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Radii of two stepped pulleys is:For crossed belt:r3 18.33 cm\n", " :r4 36.67 cm\n", " :r5 21.15 cm\n", " :r6 33.85 cm\n", "Radii of two stepped pulleys is:For open belt:r3_2 18.49 cm\n", " :r4_2 36.98 cm\n", " :r5_2 21.46 cm\n", " :r6_2 34.33 cm\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.9,Page No.403" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "d=1.2 #m #Diameter\n", "N=200 #r.p.m #Speed\n", "theta=165*pi*180**-1 #radians\n", "mu=0.3 #Coefficient of friction\n", "T1=3000 #N #MAx Tension\n", "\n", "\n", "#Calculations\n", "\n", "#Velocity\n", "v=pi*d*N*60**-1 #m/s\n", "\n", "#From ration of tensions we get\n", "#T1*T2=e**mu*theta \n", "#After simplifying we get\n", "#e**mu*theta =2.3714\n", "T2=T1*2.3714**-1 #N\n", "\n", "#Power transmitted\n", "P=(T1-T2)*v*1000**-1 #KW\n", "\n", "#Result\n", "print\"Power transmitted is\",round(P,2),\"KW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power transmitted is 21.8 KW\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.10,Page No.403" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "d1=1.20 #m #Diameter\n", "r1=0.6 #m #Radius\n", "r2=0.25 #m \n", "x=4 #m #Distance between shafts\n", "T1=1855.3 #N #Max TRension\n", "mu=0.3 #Coefficient of friction\n", "N1=200 #r.p.m\n", "\n", "#Calculations\n", "\n", "#Velocity\n", "v=pi*d1*N1*60**-1 #m/s\n", "\n", "##Let sin(alpha)=X\n", "X=(r1-r2)*x**-1\n", "alpha=arcsin(X)*(pi**-1*180)\n", "\n", "#Angle of contact\n", "theta=180-2*alpha\n", "\n", "#From equation of max tension and further simplifying we get\n", "T2=1855.3*2.435**-1 #N\n", "\n", "#Power transmitted\n", "P=(T1-T2)*v*1000**-1 #KW\n", "\n", "#Torque\n", "t1=(T1-T2)*r1 #N*m\n", "t2=(T1-T2)*r2 #Nm\n", "\n", "\n", "#Result\n", "print\"Power transmitted is\",round(P,2),\"KN\"\n", "print\"Torque Exerted on driving shaft is:t1\",round(t1,2),\"N*m\"\n", "print\" :t2\",round(t2,2),\"N*m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power transmitted is 13.74 KN\n", "Torque Exerted on driving shaft is:t1 656.02 N*m\n", " :t2 273.34 N*m\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.11,Page No.407" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "theta=2.88\n", "v=28.33 #m/s #velocity\n", "b=20 #cm #Width\n", "t=0.8 #cm #thickness\n", "rho=10**-3 #Kg/cm**3 #density\n", "f=250 #N/cm**2 #Stress\n", "mu=0.25 #coefficient of friction\n", "\n", "#Calculations\n", "\n", "#Max Tension\n", "Tm=f*b*t #N\n", "\n", "#mass\n", "m=rho*b*t*100 #Kg\n", "\n", "#Centrifugal Tension\n", "Tc=m*v**2 #N\n", "\n", "#Tension on tight side\n", "T1=Tm-Tc #N\n", "\n", "#From ratio of tension equation we get\n", "T2=T1*2.056**-1 #N\n", "\n", "#MAx Power\n", "P=(T1-T2)*v*1000**-1 #KW\n", "\n", "#Result\n", "print\"Max Power transmitted is\",round(P,2),\"KW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max Power transmitted is 39.52 KW\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.12,Page No.408" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "rho=10**-3 #kg/cm**3 #density\n", "f=250 #N/cm**2 #stress\n", "b=20 #cm #width\n", "t=1.2 #cm #thickness\n", "\n", "\n", "#Calculations\n", "\n", "#MAss\n", "m=rho*b*t*100\n", "\n", "#MAx tension\n", "Tm=f*b*t #N\n", "\n", "#Velocity\n", "v=(Tm*(3*m)**-1)**0.5 #m/s\n", "\n", "#From equation of max tension and further simplifying we get\n", "T1=2*3**-1*Tm #N\n", "T2=T1*2**-1 #N\n", "\n", "#Power \n", "P=(T1-T2)*v*(1000)**-1 #KW\n", "\n", "#Result\n", "print\"Max Power transmitted is\",round(P,2),\"KW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max Power transmitted is 57.74 KW\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.13,Page No.409" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "P=9 #KW #Power\n", "d1=1.2 #m #Diameter\n", "N1=200 #r.p.m\n", "theta=165*pi*180**-1 #radians\n", "mu=0.3 #Coefficient of friction\n", "f=140 #N/cm**2 #Stress\n", "rho=10**-3 #kg/cm**3\n", "t=1 #cm #thickness\n", "\n", "\n", "#Calculations\n", "\n", "#From Ratio of tension equation we get\n", "#T1*T2=e**mu*theta \n", "#After simplifying we get\n", "#e**mu*theta =2.3714\n", "#T1=2.3714*T2 ................1\n", "\n", "#Max tension in belt\n", "#Tm=f*b*t ..............2\n", "\n", "#Centrifugal tension\n", "#Tc=m*v**2 .....................3\n", "\n", "#Velocity\n", "v=pi*d1*N1*60**-1 #m/s\n", "\n", "#mass\n", "#m=rho*b*t*100\n", "#After simplifying we get\n", "#m=b*10**-1\n", "\n", "#Sub value of m in equation 2 and further simplfying we get\n", "#T1-T2=716.5\n", "\n", "#After further simplifying equations 1,2,3 we get\n", "T2=716.5*1.3714**-1 #N\n", "T1=2.3714*T2 #N\n", "\n", "#sub value in MAx tension and further simplifying we get\n", "b=1238.96*124**-1 #cm\n", "\n", "#Result\n", "print\"Width of belt is\",round(b,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Width of belt is 9.99 cm\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.14,Page No.411" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "b=100 #mm #Width\n", "t=10 #mm #thickness\n", "theta=2.79 #radians\n", "rho=10**-6 #kg/mm**3\n", "mu=0.25 #coefficient of friction\n", "f=1.5 #N/mm**2\n", "g=9.81 \n", "\n", "#Calculations\n", "\n", "#MAx tension\n", "Tm=f*b*t #N\n", "\n", "#From Ratio of tension equation we get\n", "#T1*T2=e**mu*theta \n", "#After simplifying we get\n", "#e**mu*theta =2\n", "\n", "#For Max power\n", "Tc=Tm*3**-1 #N\n", "\n", "#From max transmissiom equation\n", "T1=Tm-Tc\n", "T2=T1*2**-1 #N\n", "\n", "#MAss\n", "m=rho*b*t*1000 #Kg\n", "\n", "#Weight\n", "W=m*g #N\n", "\n", "#Velocity\n", "v=(Tm*(3*m)**-1)**0.5 #m/s\n", "\n", "#Power transmitted\n", "P=(T1-T2)*v*10**-3 #KW\n", "\n", "#Result\n", "print\"Max Power that can be transmitted is\",round(P,2),\"KW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max Power that can be transmitted is 11.18 KW\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.15,Page No.412" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "d1=60 #cm #diameter\n", "r1=30 #cm #Radius\n", "d2=24 #cm \n", "r2=12 #cm\n", "x=300 #cm #dist between two shafs\n", "N2=300 #r.p.m #speed of small pulley\n", "mu=0.3 #coefficient of friction\n", "m=0.6703 #kg\n", "t=100 #N per cm width #Safe working tension\n", "\n", "#Calculations\n", "\n", "#LEt sin(Alpha)=X\n", "alpha=arcsin((r1-r2)*x**-1)*(180*pi**-1)\n", "\n", "#Using equation of ratio of tension\n", "#T1*T2**-1=e**mu*theta ...........1\n", "#Simplifying furter we get value of\n", "#e**mu*theta=2.474\n", "#T1=2.474*T2 ...................1\n", "\n", "#Velocity\n", "v=pi*d2*N2*60**-1*10**-2 #m/s\n", "\n", "#Sub value of v and P in equation of power transmited and further simplifying we get\n", "#(T1-T2)=994.7 .....................2\n", "#Sub value of T1 from equation 1 we get\n", "T2=994.7*1.474**-1 #N\n", "T1=2.474*T2 #N\n", "\n", "#Min width\n", "b=T1*t**-1 #cm\n", "\n", "#Initial belt tension\n", "To=(T1+T2)*2**-1 #N\n", "\n", "#Length of belt required\n", "L=(pi*(r1+r2)+(r1+r2)**2*x**-1+2*x)*100**-1 #m\n", "\n", "#Result\n", "print\"Minimum width of belt is\",round(b,2),\"cm\"\n", "print\"Initial belt tension is\",round(To,2),\"N\"\n", "print\"Length of belt required is\",round(L,2),\"m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Minimum width of belt is 16.7 cm\n", "Initial belt tension is 1172.18 N\n", "Length of belt required is 7.38 m\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.16,Page No.414" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "d1=1.5 #m #diameter\n", "r1=0.75 #m #Radius\n", "d2=1 #m \n", "r2=0.5 #m\n", "x=4.80 #dist between two shafs\n", "To=3000 #N #Initial tension\n", "N2=600 #r.p.m #speed of small pulley\n", "mu=0.3 #coefficient of friction\n", "m=0.6703 #kg\n", "\n", "#Calculation\n", "\n", "#Velocity\n", "v=pi*d2*N2*60**-1 #m/s\n", "\n", "#Centrifugal tension\n", "Tc=m*v**2\n", "\n", "#from Initial Tensiom\n", "#T1+T2=4677 ..........1\n", "\n", "#Let sin(alpha)=X\n", "X=(r1-r2)*x**-1\n", "alpha=arcsin(X)*(pi**-1*180)\n", "\n", "#Angle of contact\n", "theta=(180-2*alpha)*pi*180**-1\n", "\n", "#From equation of ratio of tension we get\n", "#t1=2.5*T2 ...................2\n", "\n", "#sub value in equation 1 we get\n", "T2=4677*3.5**-1 #N\n", "T1=2.5*T2\n", "\n", "#Power transmitted\n", "P2=(T1-T2)*v*10**-3\n", "\n", "#Result\n", "print\"Power transmitted is\",round(P2,2),\"KW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power transmitted is 62.97 KW\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.18,Page No.418" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "alpha=25 #degrees #Angle of groove\n", "Tmax=T1=1500 #N #Max tension\n", "theta=170*pi*180**-1 #radians\n", "mu=0.27 #coefficient of friction\n", "v=2 #m/s #belt speed\n", "\n", "#Calculations\n", "\n", "#From ratio of tension\n", "#T1*T2**-1=e**mu*cosec(alpha)\n", "#AFter further simplifying we get\n", "#e**mu*cosec(alpha)=8.109\n", "T2=T1*8.109**-1 \n", "\n", "#Net driving tension\n", "T3=(T1-T2) #N\n", "\n", "#Power transmitted\n", "P=T3*v*10**-3 #W\n", "\n", "#Result\n", "print\"Net driving tension is\",round(T3,2),\"N\"\n", "print\"Power transmitted by the pulley is\",round(P,2),\"W\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Net driving tension is 1315.02 N\n", "Power transmitted by the pulley is 2.63 W\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.19,Page No.418" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "alpha=15 #Degrees\n", "t=2 #cm #Depth pf belt\n", "m=3.5*100*1000 #gm/l #mass\n", "f=140 #N/cm**2 #Allowable stress\n", "theta=140*pi*180**-1\n", "mu=0.15 #coefficient of friction\n", "\n", "#Calculations\n", "\n", "CF=2*tan(15*pi*180**-1)\n", "GC=1-2*tan(15*pi*180**-1)\n", "BC=2*GC\n", "ED=2\n", "DF=2\n", "\n", "#Area of v-belt\n", "A=(ED+BC)*2**-1*DF\n", "\n", "#MAx permissible tension\n", "Tmax=f*A #N\n", "\n", "#Centrifugal tension\n", "Tc=Tmax*3**-1 #N\n", "\n", "#Velocity\n", "v=(Tc*m**-1)**0.5*1000 #m/s\n", "\n", "#tension on tight side\n", "T1=Tmax-Tc #N\n", " \n", "#From ratio of tensions \n", "#T1*T2**-1=e*mu*thta*cosec(alpha)\n", "#After substituting values and furter simplifying we get value of\n", "#e*mu*thta*cosec(alpha)=4.12\n", "T2=T1*4.12**-1 #N\n", "\n", "#Power\n", "P2=(T1-T2)*v*1000**-1\n", "\n", "#Result\n", "print\"Max Power transmitted is\",round(P2,2),\"KW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max Power transmitted is 4.09 KW\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.20,Page No.420" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "P=75 #KW #Power\n", "d1=1.50 #m #Dia. of driver pulley\n", "N1=200 #r.p.m\n", "alpha=22.5 #Angle of groove\n", "mu=0.3 #coefficient of friction\n", "theta=160*pi*180**-1\n", "m=0.6 #kg #Mass\n", "Tmax=800 #N #Max safe\n", "\n", "#Calculations\n", "\n", "#Velocity of rope\n", "v=pi*d1*N1*60**-1 #m/s\n", "\n", "#centrifugal Tension\n", "Tc=m*v**2 #N\n", "\n", "#Tension in tight side of rope\n", "T1=Tmax-Tc #N\n", "\n", "#Ratio of tension in rope\n", "#T1*T2=e**mu*theta*cosec(alpha)\n", "#After further simplifying we get value of e**mu*theta*cosec(alpha\n", "#e**mu*theta*cosec(alpha=8.95\n", "T2=T1*8.95**-1\n", "\n", "#Power Transmitted by onr rope\n", "P2=(T1-T2)*v*1000**-1 #KW\n", "\n", "#No. of ropes required\n", "n=P*P2**-1 \n", "\n", "#Initial rope tensuion\n", "To=(T1+T2+2*Tc)*2**-1\n", "\n", "#Result\n", "print\"No. of ropes required for drive is\",round(n,2)\n", "print\"Initial Rope tension is\",round(To,2),\"N\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "No. of ropes required for drive is 8.24\n", "Initial Rope tension is 510.44 N\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.21,Page No.421" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "d1=0.40 #Dia. of pulley\n", "N1=110 #speed #r.p.m\n", "alpha=22.5 #Angle of groove\n", "mu=0.28 #coefficient of friction\n", "N=10 #No.of ropes\n", "P=23.628 #KW #Power\n", "theta=160*pi*180**-1 #radians\n", "\n", "#Calculations\n", "\n", "#velocity\n", "v=pi*d1*N1*60**-1 #m/s\n", "\n", "#Power transmited by one rope\n", "P2=P*N**-1 #KW\n", "\n", "#Centrifugal Tension\n", "#Tc=0.0281*C**2 ................1\n", "\n", "#Ratio of tension in rope\n", "#T1=7.71*T2 ...........................2\n", "\n", "#From other formula of power transmited by one rope \n", "#P2=(T1-T2)*v*1000**-1 \n", "#After further substituting and simplifying we get\n", "T2=1026*6.71**-1 #N\n", "T1=7.71*T2 #N\n", "\n", "#Tmax=T1+T2\n", "#After sub values and further simplifying we get\n", "C=(96.86)**0.5 #cm #girth of rope\n", "\n", "Tc=0.0281*C**2 #N\n", "\n", "#Initial Tension\n", "To=(T1+T2+2*Tc)*2**-1 #N\n", "\n", "#Dia. of each rope\n", "d=C*pi**-1 #cm\n", "\n", "#Result\n", "print\"Initial Tension is\",round(To,2),\"N\"\n", "print\"Dia. of each rope is\",round(d,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Initial Tension is 668.63 N\n", "Dia. of each rope is 3.13 cm\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.22,Page No.422" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "D=3.6 #m #Dia. of pulley\n", "n=15 #No. of ropes\n", "alpha=22.5 #Degrees\n", "theta=170*pi*180**-1 #Angle of contact\n", "mu=0.28 #angle of friction\n", "Tmax=960 #N #MAx tension\n", "m=1.5 #kg/l #mass of rope\n", "\n", "#Calculations\n", "\n", "#Centrifugal tension\n", "Tc=Tmax*3**-1 #N\n", "\n", "#Velocity\n", "v=(Tmax*(3*m)**-1)**0.5 #m\n", "N=60*v*(pi*D)**-1 #r.p.m\n", "\n", "#equation\n", "#T1*T2**-1=e**mu*theta*cosec(alpha)\n", "#After simlifying further we get \n", "#e**mu*theta*cosec(alpha)=8.756\n", "\n", "#Tension in tight side of rope\n", "T1=Tmax-Tc #N\n", "\n", "#Tension in slack side\n", "T2=T1*8.756**-1\n", "\n", "#Max Power\n", "P=(T1-T2)*v*1000**-1\n", "\n", "#Total max power\n", "P2=P*n\n", "\n", "#Result\n", "print\"Speed of the pulley in r.p.m is\",round(N,2),\"r.p.m\"\n", "print\"Total max power is\",round(P2,2),\"KW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Speed of the pulley in r.p.m is 77.49 r.p.m\n", "Total max power is 124.2 KW\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.23,Page No.423" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "W=9000 #N #Weight of casting\n", "n=2.5 #turns\n", "theta=5*pi #Total angle covered\n", "D=0.3 #m #diameter\n", "N=20 #Speed\n", "mu=0.25 #Coefficient of friction\n", "\n", "#Calculations\n", "\n", "#equation\n", "#W*P**-1=e**mu*theta\n", "#After simlifying further we get \n", "P=W*50.65**-1 #Tension in slack side of rope #N\n", "\n", "#Velocity\n", "v=pi*D*N*60**-1 #m/s\n", "\n", "#Power to raise casting\n", "P2=(W-P)*v*1000**-1\n", "\n", "#Result\n", "print\"Force Required by the man is\",round(P,2),\"N\"\n", "print\"Power to raise the casting is\",round(P2,2),\"N\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Force Required by the man is 177.69 N\n", "Power to raise the casting is 2.77 N\n" ] } ], "prompt_number": 6 } ], "metadata": {} } ] }