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{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 7: Belt, Rope and Chain Drive"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1, Page 228"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#Variable declaration\n",
"#given-belt is perfectly elastic and massless \n",
"u=0.3\n",
"v=3600#ft/min\n",
"V=v/60#ft/sec\n",
"theta=165#degrees\n",
"\n",
"#Calculations\n",
"x=theta*math.pi/180\n",
"k=math.e**(u*x)#k=T1/T2=e^(u*x)\n",
"To=500#lb\n",
"T1=2*k*To/(k+1)\n",
"T2=T1/k\n",
"T=T1-T2#effective tension\n",
"H=T*V/550#horsepower transmitted\n",
"\n",
"#Result\n",
"print \"The horse-power transmitted = %.2f\"%H"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The horse-power transmitted = 44.40\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2, Page 234"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#Variable declaration\n",
"w=1.2#lb/ft^2\n",
"u=0.3\n",
"v=3600#ft/min\n",
"V=v/60#ft/sec\n",
"theta=165#degrees\n",
"g=32.2#ft/s^2\n",
"\n",
"#Calculations\n",
"x=theta*math.pi/180\n",
"k=math.e**(u*x)#k=T1/T2=e^(u*x)\n",
"To=500#lb\n",
"#Solution a)Vertical drive\n",
"Tc=w*V**2/g#equation 7.5\n",
"#solution a)\n",
"H=2*(k-1)*(To-Tc)*V/((k+1)*550)\n",
"Vmax=(To*g/(3*w))**(1./2)\n",
"Hmax=2*(k-1)*(To-Tc)*Vmax/((k+1)*550)\n",
"#Solution b)\n",
"To1=To+Tc\n",
"#from equation 7.15 2/To1^2=1/Tt^2+1/Ts^2\n",
"#T1/T2=k\n",
"T2=367 #lb - from trail and error\n",
"T1=k*T2\n",
"Tt=T1+Tc\n",
"Ts=T2+Tc\n",
"HP=(T1-T2)*V/550\n",
"\n",
"#Results\n",
"print \"Solution a)\\nHorsepower transmitted= %.1f\\nMaximum Horsepower transmitted= %.1f (at velocit = %.1f ft/s^2)\"\\\n",
" \"\\n\\nSolution b)\\nTt=%.f lb\\nTs=%.f lb\\nHorsepower transmitted= %.1f\"%(H,Hmax,Vmax,Tt,Ts,HP)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Solution a)\n",
"Horsepower transmitted= 32.5\n",
"Maximum Horsepower transmitted= 36.2 (at velocit = 66.9 ft/s^2)\n",
"\n",
"Solution b)\n",
"Tt=1005 lb\n",
"Ts=501 lb\n",
"Horsepower transmitted= 54.9\n"
]
}
],
"prompt_number": 3
}
],
"metadata": {}
}
]
}
|
