{ "metadata": { "name": "", "signature": "sha256:1b022ca97a90c946dcce72b014fa00f7dd7b26ac917f0b5fe9fdd6cabd6dcdfd" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter2-TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1-pg57" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2 ILLUSRTATION 1 PAGE NO 57\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##===========================================================================================\n", "##INPUT DATA\n", "Na=300.;##driving shaft running speed in rpm\n", "Nb=400.;##driven shaft running speed in rpm\n", "Da=60.;##diameter of driving shaft in mm\n", "t=.8;##belt thickness in mm\n", "s=.05;##slip in percentage(5%)\n", "##==========================================================================================\n", "##calculation\n", "Db=(Da*Na)/Nb;##finding out the diameter of driven shaft without considering the thickness of belt\n", "Db1=(((Da+t)*Na)/Nb)-t##/considering the thickness\n", "Db2=(1.-s)*(Da+t)*(Na/Nb)-t##considering slip also\n", "##=========================================================================================\n", "##output\n", "print'%s %.1f %s'%('the value of Db is',Db,' cm')\n", "print'%s %.1f %s'%('the value of Db1 is',Db1,' cm')\n", "print'%s %.1f %s'%('the value of Db2 is',Db2,' cm')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the value of Db is 45.0 cm\n", "the value of Db1 is 44.8 cm\n", "the value of Db2 is 42.5 cm\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2-pg57" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSRTATION 2 PAGE NO 57\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "\n", "##====================================================================================\n", "##input\n", "n1=1200##rpm of motor shaft\n", "d1=40##diameter of motor pulley in cm\n", "d2=70##diameter of 1st pulley on the shaft in cm\n", "s=.03##percentage slip(3%)\n", "d3=45##diameter of 2nd pulley\n", "d4=65##diameter of the pulley on the counnter shaft\n", "##=========================================================================================\n", "##calculation\n", "n2=n1*d1*(1-s)/d2##rpm of driven shaft\n", "n3=n2##both the pulleys are mounted on the same shaft\n", "n4=n3*(1-s)*d3/d4##rpm of counter shaft\n", "\n", "##output\n", "print'%s %.1f %s %.1f %s '%('the speed of driven shaft is',n2,' rpm''the speed of counter shaft is ',n4,' rpm')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the speed of driven shaft is 665.1 rpmthe speed of counter shaft is 446.7 rpm \n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3-pg58" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2 ILLUSTRATION 3 PAGE NO:58\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##==============================================================================\n", "##input\n", "d1=30.##diameter of 1st shaft in cm\n", "d2=50.##diameter 2nd shaft in cm\n", "pi=3.141\n", "c=500.##centre distance between the shafts in cm\n", "##==============================================================================\n", "##calculation\n", "L1=((d1+d2)*pi/2.)+(2.*c)+((d1+d2)**2.)/(4.*c)##lenth of cross belt\n", "L2=((d1+d2)*pi/2.)+(2.*c)+((d1-d2)**2.)/(4.*c)##lenth of open belt\n", "r=L1-L2##remedy\n", "##==============================================================================\n", "##OUTPUT\n", "print'%s %.1f %s %.1f %s %.1f %s '%('length of cross belt is ',L1,'cm '' length of open belt is ',L2,'cm''the length of the belt to be shortened is ',r,' cm')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "length of cross belt is 1128.8 cm length of open belt is 1125.8 cmthe length of the belt to be shortened is 3.0 cm \n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex4-pg59" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "##CHAPTER 2,ILLUSTRATION 4 PAGE 59\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##====================================================================================\n", "##INPUT\n", "D1=.5## DIAMETER OF 1ST SHAFT IN m\n", "D2=.25## DIAMETER OF 2nd SHAFT IN m\n", "C=2.## CENTRE DISTANCE IN m\n", "N1=220.## SPEED OF 1st SHAFT\n", "T1=1250.## TENSION ON TIGHT SIDE IN N\n", "U=.25## COEFFICIENT OF FRICTION\n", "PI=3.141\n", "e=2.71\n", "##====================================================================================\n", "##CALCULATION\n", "L=(D1+D2)*PI/2.+((D1+D2)**2./(4.*C))+2.*C\n", "F=(D1+D2)/(2.*C)\n", "ALPHA=math.asin(F/57.3)\n", "THETA=(180.+(2.*ALPHA))*PI/180.## ANGLE OF CONTACT IN radians\n", "T2=T1/(e**(U*THETA))## TENSION ON SLACK SIDE IN N\n", "V=PI*D1*N1/60.## VELOCITY IN m/s\n", "P=(T1-T2)*V/1000.## POWER IN kW\n", "##====================================================================================\n", "##OUTPUT\n", "print'%s %.1f %s'%('LENGTH OF BELT REQUIRED =',L,' m')\n", "print'%s %.1f %s'%('ANGLE OF CONTACT =',THETA,' radians')\n", "print'%s %.1f %s'%('POWER CAN BE TRANSMITTED=',P,' kW')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "LENGTH OF BELT REQUIRED = 5.2 m\n", "ANGLE OF CONTACT = 3.1 radians\n", "POWER CAN BE TRANSMITTED= 3.9 kW\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex5-pg59" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 5 PAGE 5\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##=====================================================================================================\n", "##input\n", "n1=100.## of driving shaft\n", "n2=240.##speed of driven shaft\n", "p=11000.##power to be transmitted in watts\n", "c=250.##centre distance in cm\n", "d2=60.##diameter in cm\n", "b=11.5*10**-2##width of belt in metres\n", "t=1.2*10**-2##thickness in metres\n", "u=.25##co-efficient of friction \n", "pi=3.141\n", "e=2.71\n", "##===================================================================================================\n", "##calculation for open bely drive\n", "d1=n2*d2/n1\n", "f=(d1-d2)/(2.*c)##sin(alpha) for open bely drive\n", "##angle of arc of contact for open belt drive is,theta=180-2*alpha\n", "alpha=math.asin(f)*57.3\n", "teta=(180.-(2*alpha))*3.147/180.##pi/180 is used to convert into radians\n", "x=(e**(u*teta))##finding out the value of t1/t2\n", "v=pi*d2*10.*n2/60.##finding out the value of t1-t2\n", "y=p*1000./(v)\n", "t1=(y*x)/(x-1.)\n", "Fb=t1/(t*b)/1000.\n", "##=======================================================================================================\n", "##calculation for cross belt drive bely drive\n", "F=(d1+d2)/(2.*c)##for cross belt drive bely drive\n", "ALPHA=math.asin(F)*57.3\n", "THETA=(180.+(2.*ALPHA))*pi/180.##pi/180 is used to convert into radians\n", "X=(e**(u*THETA))##finding out the value of t1/t2\n", "V=pi*d2*10.*n2/60.##finding out the value of t1-t2\n", "Y=p*1000./(V)\n", "T1=(Y*X)/(X-1.)\n", "Fb2=T1/(t*b)/1000.\n", "##========================================================================================================\n", "##output\n", "print('for a open belt drive:')\n", "print'%s %.1f %s %.1f %s'%('the tension in belt is ',t1,'N' 'stress induced is ',Fb,' kN/m**2')\n", "print('for a cross belt drive:')\n", "print'%s %.1f %s %.1f %s '%('the tension in belt is ',T1,'N' 'stress induced is ',Fb2,' kN/m**2')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "for a open belt drive:\n", "the tension in belt is 2898.4 Nstress induced is 2100.3 kN/m**2\n", "for a cross belt drive:\n", "the tension in belt is 2318.8 Nstress induced is 1680.3 kN/m**2 \n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex6-pg61" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 6 PAGE 61\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##========================================================================================\n", "##INPUT\n", "D1=80.##DIAMETER OF SHAFT IN cm\n", "N1=160.##SPEED OF 1ST SHAFT IN rpm\n", "N2=320.##SPEED OF 2ND SHAFT IN rpm\n", "C=250.##CENTRE DISTANCE IN CM\n", "U=.3##COEFFICIENT OF FRICTION\n", "P=4.##POWER IN KILO WATTS\n", "e=2.71\n", "PI=3.141\n", "f=110.##STRESS PER cm WIDTH OF BELT\n", "##========================================================================================\n", "##CALCULATION\n", "V=PI*D1*math.pow(10,-2)*N1/60.##VELOCITY IN m/s\n", "Y=P*1000./V##Y=T1-T2\n", "D2=D1*(N1/N2)##DIAMETER OF DRIVEN SHAFT\n", "F=(D1-D2)/(2.*C)\n", "ALPHA=math.asin(F/57.3)\n", "THETA=(180.-(2.*ALPHA))*PI/180.##ANGLE OF CONTACT IN radians\n", "X=e**(U*THETA)##VALUE OF T1/T2\n", "T1=X*Y/(X-1.)\n", "b=T1/f##WIDTH OF THE BELT REQUIRED \n", "##=======================================================================================\n", "##OUTPUT\n", "print'%s %.1f %s'%('THE WIDTH OF THE BELT IS ',b,' cm')\n", "#apporximate ans is correct " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "THE WIDTH OF THE BELT IS 8.9 cm\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex7-pg62" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2 ILLUSRTATION 7 PAGE NO 62\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "\n", "##===========================================================================================\n", "##INPUT DATA\n", "m=1000.## MASS OF THE CASTING IN kg\n", "PI=3.141\n", "THETA=2.75*2*PI## ANGLE OF CONTACT IN radians\n", "D=.26## DIAMETER OF DRUM IN m\n", "N=24.## SPEED OF THE DRUM IN rpm\n", "U=.25## COEFFICIENT OF FRICTION\n", "e=2.71\n", "T1=9810## TENSION ON TIGHTSIDE IN N\n", "##=============================================================================================\n", "##CALCULATION\n", "T2=T1/(e**(U*THETA))## tension on slack side of belt in N\n", "W=m*9.81## WEIGHT OF CASTING IN N\n", "R=D/2.## RADIUS OF DRUM IN m\n", "P=2*PI*N*W*R/60000.## POWER REQUIRED IN kW\n", "P2=(T1-T2)*PI*D*N/60000.## POWER SUPPLIED BY DRUM IN kW\n", "##============================================================================================\n", "##OUTPUT\n", "print'%s %.1f %s %.1f %s %.1f %s '%('FORCE REQUIRED BY MAN=',T2,' N'and 'POWER REQUIRED TO RAISE CASTING=',P,' kW' 'POWER SUPPLIED BY DRUM=',P2,' kW')\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "FORCE REQUIRED BY MAN= 132.4 POWER REQUIRED TO RAISE CASTING= 3.2 kWPOWER SUPPLIED BY DRUM= 3.2 kW \n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex8-pg62" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 8 PAGE 62\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##INPUT\n", "t=9.##THICKNESS IN mm\n", "b=250.##WIDTH IN mm\n", "D=90.##DIAMETER OF PULLEY IN cm\n", "N=336.##SPEED IN rpm\n", "PI=3.141\n", "U=.35##COEFFICIENT FRICTION\n", "e=2.71\n", "THETA=120.*PI/180.\n", "Fb=2.##STRESS IN MPa\n", "d=1000.##DENSITY IN KG/M**3\n", "\n", "##CALCULATION\n", "M=b*10**-3.*t*10**-3.*d##MASS IN KG\n", "V=PI*D*10**-2.*N/60.##VELOCITY IN m/s\n", "Tc=M*V**2##CENTRIFUGAL TENSION\n", "Tmax=b*t*Fb##MAX TENSION IN N\n", "T1=Tmax-Tc\n", "T2=T1/(e**(U*THETA))\n", "P=(T1-T2)*V/1000.\n", "\n", "##OUTPUT\n", "print'%s %.1f %s'%('THE TENSION ON TIGHT SIDE OF THE BELT IS',T1,' N')\n", "print'%s %.1f %s'%('THE TENSION ON SLACK SIDE OF THE BELT IS ',T2,' N')\n", "print'%s %.1f %s'%('CENTRIFUGAL TENSION =',Tc,'N')\n", "print'%s %.1f %s'%('THE POWER CAPACITY OF BELT IS ',P,' KW')\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "THE TENSION ON TIGHT SIDE OF THE BELT IS 3936.1 N\n", "THE TENSION ON SLACK SIDE OF THE BELT IS 1895.6 N\n", "CENTRIFUGAL TENSION = 563.9 N\n", "THE POWER CAPACITY OF BELT IS 32.3 KW\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex9-pg63" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 9 PAGE 63\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##INPUT\n", "P=35000.##POWER TO BE TRANSMITTED IN WATTS\n", "D=1.5##EFFECTIVE DIAMETER OF PULLEY IN METRES\n", "N=300.##SPEED IN rpm\n", "e=2.71\n", "U=.3##COEFFICIENT OF FRICTION\n", "PI=3.141\n", "THETA=(11/24.)*360.*PI/180.##ANGLE OF CONTACT\n", "density=1.1##density of belt material in Mg/m**3\n", "L=1.##in metre\n", "t=9.5##THICKNESS OF BELT IN mm\n", "Fb=2.5##PERMISSIBLE WORK STRESS IN N/mm**2\n", "\n", "##CALCULATION\n", "V=PI*D*N/60.##VELOCITY IN m/s\n", "X=P/V##X=T1-T2\n", "Y=e**(U*THETA)##Y=T1/T2\n", "T1=X*Y/(Y-1)\n", "Mb=t*density*L/10**3.##value of m/b\n", "Tc=Mb*V**2.##centrifugal tension/b\n", "Tmaxb=t*Fb##max tension/b\n", "b=T1/(Tmaxb-Tc)##thickness in mm\n", "##output\n", "print'%s %.1f %s'%('TENSION IN TIGHT SIDE OF THE BELT =',T1,' N')\n", "print'%s %.1f %s'%('THICKNESS OF THE BELT IS =',b,' mm')\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "TENSION IN TIGHT SIDE OF THE BELT = 2573.5 N\n", "THICKNESS OF THE BELT IS = 143.4 mm\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex10-pg64" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 10 PAGE 64\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##INPUT\n", "t=5.##THICKNESS OF BELT IN m\n", "PI=3.141\n", "U=.3\n", "e=2.71\n", "THETA=155.*PI/180.##ANGLE OF CONTACT IN radians\n", "V=30.##VELOCITY IN m/s\n", "density=1.##in m/cm**3\n", "L=1.##LENGTH\n", "\n", "##calculation\n", "Xb=80.## (T1-T2)=80b;so let (T1-T2)/b=Xb\n", "Y=e**(U*THETA)## LET Y=T1/T2\n", "Zb=80.*Y/(Y-1.)## LET T1/b=Zb;BY SOLVING THE ABOVE 2 EQUATIONS WE WILL GET THIS EXPRESSION\n", "Mb=t*L*density*10**-2.## m/b in N\n", "Tcb=Mb*V**2.## centrifugal tension/b\n", "Tmaxb=Zb+Tcb## MAX TENSION/b\n", "Fb=Tmaxb/t##STRESS INDUCED IN TIGHT BELT\n", "\n", "##OUTPUT\n", "print'%s %.1f %s'%('THE STRESS DEVELOPED ON THE TIGHT SIDE OF BELT=',Fb,' N/cm**2')\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "THE STRESS DEVELOPED ON THE TIGHT SIDE OF BELT= 37.8 N/cm**2\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex11-pg65" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 11 PAGE 65\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##INPUT\n", "C=4.5## CENTRE DISTANCE IN metres\n", "D1=1.35## DIAMETER OF LARGER PULLEY IN metres\n", "D2=.9## DIAMETER OF SMALLER PULLEY IN metres\n", "To=2100.## INITIAL TENSION IN newtons\n", "b=12.## WIDTH OF BELT IN cm\n", "t=12.## THICKNESS OF BELT IN mm\n", "d=1.## DENSITY IN gm/cm**3\n", "U=.3## COEFFICIENT OF FRICTION\n", "L=1.## length in metres\n", "PI=3.141\n", "e=2.71\n", "\n", "##CALCULATION\n", "M=b*t*d*L*10**-2.## mass of belt per metre length in KG\n", "V=(To/3./M)**.5## VELOCITY OF FOR MAX POWER TO BE TRANSMITTED IN m/s\n", "Tc=M*V**2.## CENTRIFUGAL TENSION IN newtons\n", "## LET (T1+T2)=X\n", "X=2.*To-2.*Tc ## THE VALUE OF (T1+T2)\n", "F=(D1-D2)/(2.*C)\n", "ALPHA=math.asin(F/57.3)\n", "THETA=(180.-(2.*ALPHA))*PI/180.## ANGLE OF CONTACT IN radians\n", "## LET T1/T2=Y\n", "Y=e**(U*THETA)## THE VALUE OF T1/T2\n", "T1=X*Y/(Y+1.)## BY SOLVING X AND Y WE WILL GET THIS EQN\n", "T2=X-T1\n", "P=(T1-T2)*V/1000.## MAX POWER TRANSMITTED IN kilowatts\n", "N1=V*60./(PI*D1)## SPEED OF LARGER PULLEY IN rpm\n", "N2=V*60./(PI*D2)## SPEED OF SMALLER PULLEY IN rpm\n", "##OUTPUT\n", "print'%s %.1f %s'%(' MAX POWER TO BE TRANSMITTED =',P,' KW')\n", "print'%s %.1f %s'%(' SPEED OF THE LARGER PULLEY =',N1,' rpm')\n", "print'%s %.1f %s'%(' SPEED OF THE SMALLER PULLEY =',N2,' rpm')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " MAX POWER TO BE TRANSMITTED = 27.0 KW\n", " SPEED OF THE LARGER PULLEY = 312.0 rpm\n", " SPEED OF THE SMALLER PULLEY = 468.0 rpm\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex12-pg66" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 12 PAGE 66\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##============================================================================================================================\n", "##INPUT\n", "PI=3.141\n", "e=2.71\n", "D1=1.20## DIAMETER OF DRIVING SHAFT IN m\n", "D2=.50## DIAMETER OF DRIVEN SHAFT IN m\n", "C=4.## CENTRE DISTANCE BETWEEN THE SHAFTS IN m\n", "M=.9## MASS OF BELT PER METRE LENGTH IN kg\n", "Tmax=2000## MAX TENSION IN N\n", "U=.3## COEFFICIENT OF FRICTION\n", "N1=200.## SPEED OF DRIVING SHAFT IN rpm\n", "N2=450.## SPEED OF DRIVEN SHAFT IN rpm\n", "##==============================================================================================================================\n", "##CALCULATION\n", "V=PI*D1*N1/60.## VELOCITY OF BELT IN m/s\n", "Tc=M*V**2.## CENTRIFUGAL TENSION IN N\n", "T1=Tmax-Tc## TENSION ON TIGHTSIDE IN N\n", "F=(D1-D2)/(2.*C)\n", "ALPHA=math.asin(F/57.3)\n", "THETA=(180.-(2.*ALPHA))*PI/180.## ANGLE OF CONTACT IN radians\n", "T2=T1/(e**(U*THETA))## TENSION ON SLACK SIDE IN N\n", "TL=(T1-T2)*D1/2.## TORQUE ON THE SHAFT OF LARGER PULLEY IN N-m\n", "TS=(T1-T2)*D2/2.## TORQUE ON THE SHAFT OF SMALLER PULLEY IN N-m\n", "P=(T1-T2)*V/1000.## POWER TRANSMITTED IN kW\n", "Pi=2.*PI*N1*TL/60000.## INPUT POWER\n", "Po=2.*PI*N2*TS/60000.## OUTPUT POWER\n", "Pl=Pi-Po## POWER LOST DUE TO FRICTION IN kW\n", "n=Po/Pi*100.## EFFICIENCY OF DRIVE IN %\n", "##==================================================================================================================================\n", "##OUTPUT\n", "print'%s %.1f %s'%('TORQUE ON LARGER SHAFT =',TL,'N-m')\n", "print'%s %.1f %s'%('TORQUE ON SMALLER SHAFT =',TS,' N-m')\n", "print'%s %.1f %s'%('POWER TRANSMITTED =',P,' kW')\n", "print'%s %.1f %s'%('POWER LOST DUE TO FRICTION =',Pl,' kW')\n", "print'%s %.1f %s'%('EFFICIENCY OF DRINE =',n,' percentage')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "TORQUE ON LARGER SHAFT = 679.0 N-m\n", "TORQUE ON SMALLER SHAFT = 282.9 N-m\n", "POWER TRANSMITTED = 14.2 kW\n", "POWER LOST DUE TO FRICTION = 0.9 kW\n", "EFFICIENCY OF DRINE = 93.8 percentage\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex13-pg67" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 13 PAGE 67\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##============================================================================================================================\n", "##INPUT\n", "PI=3.141\n", "e=2.71\n", "P=90## POWER OF A COMPRESSOR IN kW\n", "N2=250.## SPEED OF DRIVEN SHAFT IN rpm\n", "N1=750.## SPEED OF DRIVER SHAFT IN rpm\n", "D2=1.## DIAMETER OF DRIVEN SHAFT IN m\n", "C=1.75## CENTRE DISTANCE IN m\n", "V=1600./60.## VELOCITY IN m/s\n", "a=375.## CROSECTIONAL AREA IN mm**2\n", "density=1000.## BELT DENSITY IN kg/m**3\n", "L=1## length to be considered\n", "Fb=2.5## STRESSS INDUCED IN MPa\n", "beeta=35./2.## THE GROOVE ANGLE OF PULLEY\n", "U=.25## COEFFICIENT OF FRICTION\n", "##=================================================================================================================================\n", "##CALCULATION\n", "D1=N2*D2/N1## DIAMETER OF DRIVING SHAFT IN m\n", "m=a*density*10**-6.*L## MASS OF THE BELT IN kg\n", "Tmax=a*Fb## MAX TENSION IN N\n", "Tc=m*V**2.## CENTRIFUGAL TENSION IN N\n", "T1=Tmax-Tc## TENSION ON TIGHTSIDE OF BELT IN N\n", "F=(D2-D1)/(2.*C)\n", "ALPHA=math.asin(F/57.3)\n", "THETA=(180.-(2.*ALPHA))*PI/180.## ANGLE OF CONTACT IN radians\n", "T2=T1/(e**(U*THETA/math.sin(beeta/57.3)))##TENSION ON SLACKSIDE IN N\n", "P2=(T1-T2)*V/1000.## POWER TRANSMITTED PER BELT kW\n", "N=P/P2## NO OF V-BELTS\n", "N3=N+1.\n", "##======================================================================================================================================\n", "##OUTPUT\n", "print'%s %.1f %s %.1f %s '%('NO OF BELTS REQUIRED TO TRANSMIT POWER=',N,' APPROXIMATELY=',N3,'')\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "NO OF BELTS REQUIRED TO TRANSMIT POWER= 5.4 APPROXIMATELY= 6.4 \n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex14-pg68" ] }, { "cell_type": "code", "collapsed": false, "input": [ "##CHAPTER 2,ILLUSTRATION 14 PAGE 68\n", "##TITLE:TRANSMISSION OF MOTION AND POWER BY BELTS AND PULLEYS\n", "import math\n", "##============================================================================================================================\n", "##INPUT\n", "PI=3.141\n", "e=2.71\n", "P=75.## POWER IN kW\n", "D=1.5## DIAMETER OF PULLEY IN m\n", "U=.3## COEFFICIENT OF FRICTION\n", "beeta=45./2.## GROOVE ANGLE\n", "THETA=160.*PI/180.## ANGLE OF CONTACT IN radians\n", "m=.6## MASS OF BELT IN kg/m\n", "Tmax=800.## MAX TENSION IN N\n", "N=200.## SPEED OF SHAFT IN rpm\n", "##=============================================================================================================================\n", "##calculation\n", "V=PI*D*N/60.## VELOCITY OF ROPE IN m/s\n", "Tc=m*V**2.## CENTRIFUGAL TENSION IN N\n", "T1=Tmax-Tc## TENSION ON TIGHT SIDE IN N\n", "T2=T1/(e**(U*THETA/math.sin(beeta/57.3)))##TENSION ON SLACKSIDE IN N\n", "P2=(T1-T2)*V/1000.## POWER TRANSMITTED PER BELT kW\n", "No=P/P2## NO OF V-BELTS\n", "N3=No+1.## ROUNDING OFF\n", "To=(T1+T2+Tc*2.)/2.## INITIAL TENSION\n", "##================================================================================================================================\n", "##OUTPUT\n", "print'%s %.1f %s %.1f %s '%('NO OF BELTS REQUIRED TO TRANSMIT POWER=',No,'' 'APPROXIMATELY=',N3,'')\n", "print'%s %.1f %s'%('INITIAL ROPE TENSION=',To,' N')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "NO OF BELTS REQUIRED TO TRANSMIT POWER= 8.3 APPROXIMATELY= 9.3 \n", "INITIAL ROPE TENSION= 510.8 N\n" ] } ], "prompt_number": 16 } ], "metadata": {} } ] }