{
"metadata": {
"name": "",
"signature": "sha256:4d8f50c55aa5f869a3b91c9992fbc1206b0fe54a3763477766a504a0fd20f355"
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Ch:28 Worm and worm wheel set"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 28-1 - Page 726"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from math import sqrt, pi\n",
"Z1=1#\n",
"Z2=30#\n",
"q=10#\n",
"m=5#\n",
"d=q*m#\n",
"D=m*Z2#\n",
"#let the speed reduction ratio be G\n",
"G=Z2/Z1#\n",
"CD=(d+D)/2#\n",
"print \"G is %0.0f \"%(G)#\n",
"print \"\\nCD is %0.0f mm \"%(CD)#\n",
"print \"\\nd is %0.0f mm \"%(d)#\n",
"print \"\\nD is %0.0f mm \"%(D)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"G is 30 \n",
"\n",
"CD is 100 mm \n",
"\n",
"d is 50 mm \n",
"\n",
"D is 150 mm \n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 28-2 - Page 726"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import tan, atan, cos\n",
"Z1=1#\n",
"Z2=52#\n",
"q=10#\n",
"m=8#\n",
"i=Z2/Z1#\n",
"CD=((m*q)+(m*Z2))/2#\n",
"lamda=atan(Z1/q)#\n",
"d=q*m#\n",
"da=m*(q+2)#\n",
"df=m*(q+2-(4.4*cos(lamda)))#\n",
"pa=m*pi#\n",
"D=m*Z2#\n",
"Da=m*(Z2+(4*cos(lamda))-2)#\n",
"Df=m*(Z2-2-(0.4*cos(lamda)))#\n",
"print \"i is %0.0f \"%(i)#\n",
"print \"\\nCD is %0.0f mm \"%(CD)#\n",
"print \"\\npa is %0.2f mm \"%(pa)#\n",
"print \"\\nda is %0.0f mm \"%(da)#\n",
"print \"\\ndf is %0.3f mm \"%(df)#\n",
"print \"\\nDa is %0.3f mm \"%(Da)#\n",
"print \"\\nDf is %0.3f mm \"%(Df)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"i is 52 \n",
"\n",
"CD is 248 mm \n",
"\n",
"pa is 25.13 mm \n",
"\n",
"da is 96 mm \n",
"\n",
"df is 60.975 mm \n",
"\n",
"Da is 431.841 mm \n",
"\n",
"Df is 396.816 mm \n"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 28-3 - Page 727"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sin\n",
"Z1=2#\n",
"Z2=60#\n",
"q=10#\n",
"m=5#\n",
"P=6000#\n",
"N=1440#\n",
"u=0.08#\n",
"alpha=20*pi/180#\n",
"lamda=atan(Z1/q)#\n",
"d=m*q#\n",
"w=2*pi*N/60#\n",
"T=P/w#\n",
"Ptw=T*10**3/(d/2)#\n",
"a=cos(alpha)#\n",
"b=cos(lamda)#\n",
"x=sin(alpha)#\n",
"y=sin(lamda)#\n",
"Paw=Ptw*(((a*b)-(u*y))/((a*y)+(u*b)))#\n",
"Prw=Ptw*y/((a*y)+(u*b))#\n",
"#Paw=Ptw*((cos(alpha)*cos(lambda))-(u*sin(lambda)))/((cos(alpha)*sin(lambda))+(u*cos(lambda)))#\n",
"#Prw=Ptw*((sin(alpha))/((cos(alpha)*sin(lambda))+(u*cos(lambda))))#\n",
"print \"Ptw=Pag is %0.1f N \"%(Ptw)#\n",
"print \"\\nPaw=Ptg is %0.0f N \"%(Paw)#\n",
"print \"\\nPrw=Prg is %0.0f N \"%(Prw)#\n",
" \n",
"#The difference in the value is due to rounding-off the values."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Ptw=Pag is 1591.5 N \n",
"\n",
"Paw=Ptg is 5487 N \n",
"\n",
"Prw=Prg is 1188 N \n"
]
}
],
"prompt_number": 10
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 28-4 - Page 728"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"Z1=2#\n",
"Z2=40#\n",
"q=8#\n",
"m=5#\n",
"d=q*m#\n",
"P=1.2#\n",
"lamda=atan(Z1/q)#\n",
"N=1000#\n",
"Vt=2*pi*N*20/(60*1000)#\n",
"Vs=Vt/cos(lamda)#\n",
"u=0.032#\n",
"alpha=20*pi/180#\n",
"x=cos(alpha)#\n",
"y=tan(lamda)#\n",
"z=(cos(lamda))/sin(lamda)#\n",
"n=(x-(u*y))/(x+(u*z))#\n",
"#Let power output be Po\n",
"Po=P*n#\n",
"#Let power lost in friction be Pf\n",
"Pf=P-Po#\n",
"print \"P is %0.1f kW \"%(P)#\n",
"print \"\\nPo is %0.3f kW \"%(Po)#\n",
"print \"\\nPf is %0.3f kW \"%(Pf)#\n",
" "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"P is 1.2 kW \n",
"\n",
"Po is 1.047 kW \n",
"\n",
"Pf is 0.153 kW \n"
]
}
],
"prompt_number": 11
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 28-5 - Page 729"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"Z1=2#\n",
"Z2=54#\n",
"q=10#\n",
"m=8#\n",
"P=4000#\n",
"A=1.8#\n",
"K=16#\n",
"N=1000#\n",
"u=0.028#\n",
"lamda=atan(Z1/q)#\n",
"alpha=20*pi/180#\n",
"d=m*q#\n",
"Vt=2*pi*N*d/(2*60*1000)#\n",
"Vs=Vt/cos(lamda)#\n",
"x=cos(alpha)#\n",
"y=tan(lamda)#\n",
"z=(cos(lamda))/sin(lamda)#\n",
"n=(x-(u*y))/(x+(u*z))#\n",
"delT=P*(1-n)/(K*A)#\n",
"print \"n is %0.3f \"%(n)#\n",
"print \"\\ndelT is %0.2f deg \"%(delT)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"n is 0.865 \n",
"\n",
"delT is 18.73 deg \n"
]
}
],
"prompt_number": 12
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 28-6 - Page 729"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"Z1=1#\n",
"Z2=30#\n",
"q=10#\n",
"m=6#\n",
"#Let the ultimate strength of gear is sigut\n",
"#Let the allowable strenth of wheel is sigb\n",
"sigut=450#\n",
"sigb=84#\n",
"N=1200#\n",
"n=N/Z2#\n",
"alpha=20*pi/180#\n",
"d=m*q#\n",
"D=Z2*m#\n",
"b=3*d/4#\n",
"V=2*pi*n*D/(2*60*1000)#\n",
"Cv=6/(6+V)#\n",
"y=0.154-(0.912/Z2)#\n",
"Y=pi*y#\n",
"Sb=sigb*b*Cv*m*Y#\n",
"K=0.415#\n",
"Sw=b*D*K#\n",
"print \"Sb is %0.0f N \"%(Sb)#\n",
"print \"\\nSw is %0.0f N \"%(Sw)#\n",
"\n",
"#The difference in the value of Sb is due to rounding-off the values."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Sb is 8286 N \n",
"\n",
"Sw is 3362 N \n"
]
}
],
"prompt_number": 13
}
],
"metadata": {}
}
]
}