Page 217 - Modular design for machine tools

Basic Knowledge of Machine Tool Joints 177

∆Xφ a = ∆φ a ·H
∆X ∆X
∆Xφ a 0

P = 4000 kgf

Column

H

∆φ a

Base

Overall Deflection Deflection H
deflection due to joint of column
% % % mm

No joint 8 92 1000
separation
15 85 500
100
With joint 12 88 1000
separation
22 78 500
Figure 5-2 Influencing rate of joint to overall deflection of bolted column for
horizontal boring and milling machine (by Píˇ c).

with that of an equivalent solid structure, where equivalent solid means
the structure having the same shape and dimensions, but no joints. In
addition, the designer must be aware that the joint exerts a consider-
able influence on the total stiffness of a machine tool as a whole, when
the joint exists within the FOF ( flow of force, der Kraftflu , see Part 1).
In contrast, the damping capacity increases obviously, e.g., in the case
of the main spindle of the horizontal boring and milling machine, as