Page 234 - Modular design for machine tools

194 Engineering Design for Machine Tool Joints

F y
y
x z
M xz
F , F y , F z : Components of
x
cutting force

Z

F F x
F x z
M xy M yz
X
F z
F y

Loading conditions of column
z
F x , F : Bending loads
F : Axial load
y
M , M : Bending moments
xy
yz
Loading due to cutting force (M = F X, M = F · Z)
yz
y
y
xy
M : Torsional moment
xz
( M = F X – F Z )
x
xz
z
(a)
T, f T T, f 0
P P
d d 0
= P/d K = P/d
K SB 0B 0
K = T/f T K = T/f
ST
T
0T
0
Column Suppositive
fix end
Base
Column with bolted joint Equivalent solid column
(b)
Figure 5-16 Stiffness expression for bolted joint in engineering calculation: (a) Complicated
loading conditions in a floor type horizontal boring and milling machine and (b) expression
for relative joint stiffness.