Ch:4 Manufacturing considerations

exa 4-1 - Page 112

In [1]:
from math import sqrt
d=70#
dmin=50#
dmax=80#
D=sqrt(dmin*dmax)#
D=63#
i=0.458*(D**(1/3))+(0.001*D)#

#standard tolerance for H8 is ST1
ST1=25*i#
ST1=ST1*10**-3#
#standard tolerance of shaft for grade g7 is ST2
ST2=16*i#
ST2=ST2*10**-3#
es=-(2.5*(D**0.333))#
es=es*10**-3#
ei=es-ST2#
#Lower limit for hole is LLH
#Upper limit for hole is ULH
#Upper limit for shaft is ULS
#Lower limit for shaft is LLS
LLH=d#
ULH=LLH+ST1#
ULS=LLH+es#
LLS=ULS-ST2#
#Maximum clearance is Cmax
#minimum clearance is Cmin
Cmax=ULH-LLS#
Cmin=LLH-ULS#
# printing data in scilab o/p window
print " LLH is %0.1f mm "%(LLH)#
print "\n ULH is %0.3f mm "%(ULH)#
print "\n ULS is %0.2f mm "%(ULS)#
print "\n LLS is %0.2f mm "%(LLS)#
print "\n Cmax is %0.3f mm "%(Cmax)#
print "\n Cmin is %0.3f mm "%(Cmin)#

 LLH is 70.0 mm 

 ULH is 70.013 mm 

 ULS is 69.99 mm 

 LLS is 69.98 mm 

 Cmax is 0.031 mm 

 Cmin is 0.010 mm

exa 4-2 - Page 112

In [2]:
d=25#
#Lower limit for hole is LLH
#Upper limit for hole is ULH
#Upper limit for shaft is ULS
#Lower limit for shaft is LLS
ULH=d+0.021#
LLH=d+0#
ULS=d+0.041#
LLS=d+0.028#
#Maximum interference is Cmax
#minimum interference is Cmin
Cmax=ULS-LLH#
Cmin=LLS-ULH#
# printing data in scilab o/p window
print "Cmax is %0.3f mm "%(Cmax)#
print "\nCmin is %0.3f mm "%(Cmin)#

Cmax is 0.041 mm 

Cmin is 0.007 mm

exa 4-3 - Page 113

In [3]:
d=50#
Es=0.039#
Ei=0#
es=-9*10**-3#
ei=-34*10**-3#
#Shaft dia is D
D=d+es#
#Lower limit for hole is LLH
#Upper limit for hole is ULH
#Upper limit for shaft is ULS
#Lower limit for shaft is LLS
ULH=d+Es#
LLH=d+Ei#
ULS=d+es#
LLS=d+ei#
#Maximum interference is Cmax
#minimum interference is Cmin
Cmax=ULH-LLS#
Cmin=LLH-ULS#
  # printing data in scilab o/p window
print " ULH is %0.3f mm "%(ULH)#
print "\n LLH is %0.3f mm "%(LLH)#
print "\n ULS is %0.3f mm "%(ULS)#
print "\n LLS is %0.3f mm "%(LLS)#
print "\n Cmax is %0.3f mm "%(Cmax)#
print "\n Cmin is %0.3f mm "%(Cmin)#
print ' Therefore, H8g7 is easy running fit'

 ULH is 50.039 mm 

 LLH is 50.000 mm 

 ULS is 49.991 mm 

 LLS is 49.966 mm 

 Cmax is 0.073 mm 

 Cmin is 0.009 mm 
 Therefore, H8g7 is easy running fit

exa 4-4 - Page 114

In [4]:
d=30#
Es=0.025#
Ei=0#
es=11*10**-3#
ei=-5*10**-3#
#Shaft dia is D
D=d+es#
#Lower limit for hole is LLH
#Upper limit for hole is ULH
#Upper limit for shaft is ULS
#Lower limit for shaft is LLS
ULH=d+Es#
LLH=d+Ei#
ULS=d+es#
LLS=d+ei#
#Maximum interference is Cmax
#minimum interference is Cmin
Cmax=ULH-LLS#
Cmin=ULS-LLH##

  # printing data in scilab o/p window
print " ULH is %0.3f mm "%(ULH)#
print "\n LLH is %0.3f mm "%(LLH)#
print "\n ULS is %0.3f mm "%(ULS)#
print "\n LLS is %0.3f mm "%(LLS)#
print "\n Cmax is %0.3f mm "%(Cmax)#
print "\n Cmin is %0.3f mm "%(Cmin)#

 ULH is 30.025 mm 

 LLH is 30.000 mm 

 ULS is 30.011 mm 

 LLS is 29.995 mm 

 Cmax is 0.030 mm 

 Cmin is 0.011 mm