Page 245 - Modular design for machine tools

Basic Knowledge of Machine Tool Joints 205

In retrospect, there were some symptoms for revealing the impor-
tance of the machine tool joint. For instance, Prof. Meyer of Technische
Hogeschool in Delft aimed once at the reinforcement of the press-fit
portion in the crankshaft for a large-size ship diesel engine without
enlarging its size. He conducted a cooperative work with Technische
Hochschule Berlin under the control of Prof. Kienzle from 1928 to 1942,
and Prof. Meyer clarified the reinforcement effect of the hard particle
when applying it to the interface of the single flat joint under normal
preload and shear force. In addition, Meyer observed the normal joint
deflection by the preload and the nonlinear relationship between the
shear force and the corresponding displacement, and duly suggested the
dominant role of the joint in the machine tool structure [25]. Following
this cooperative work, Kienzle and Kettner [1] showed evidence in 1939
in which the damping capacity of the welded structure was, as already
stated, larger than that of equivalent cast structure, and they implied
that the welded joint itself is a major cause of this interesting behavior.
Thus, we can assert that the first academic research into the joint could
be credited to Kienzle in 1939. In fact, the work of Kienzle was carried
out to establish a method by which the production time of machine tools
could be shortened to respond to the rapidly increasing production
volume of the war supplies during World War II.
Figures 5-24 and 5-25 are one of the quick notes to understand the
history of research into the machine tool joint in earlier days. In short,
Fig. 5-24 shows the ascending and descending flow of the representative
research work and subjects in every country, and from it we can under-
stand the diversification trends of the research activities along with
implicit mutual influence when the research work was conducted. In
contrast, Fig. 5-25 shows explicitly the importance of the human network,
information exchange, information transfer by publications, and so on,
when the research work was carried out. This is research into the bolted
joint and consequent concerns; however, we can expect to have similar
results when changing the objective research subject. It is very inter-
esting to know that the world is very small and how the information flies
speedily.
Intuitively, it can be seen that the core research works were carried
out using mostly the simple flat joint at this stage by choosing the rep-
resentative joints, e.g., slideway, rolling bearing, and bolted joint. We can
thus clarify the basic behavior of the machine tool joint, although not
everything has been unveiled. The root cause of some remaining prob-
lems at this stage was the lack of effective computational and experi-
mental techniques. In contrast, these earlier works dispelled some old
myths. For instance, a famous maxim for the design of the bolted joint,
i.e., Rötscher’s pressure cone (see Chap. 7), has been verified as apply-
ing to only a specified joint; however, a considerable number of designers,