Problem równowagi statycznej napędu przy momentach bezwładności zależnych od drogi

Abstract

There are some cases when inertia of given driving system is not constant. The conditions of stable collaboration of driving motor with driven mechanism with constant inertia at steady- state are well known. But there do exist several machines with varying inertia. Most common cases are concerned with electric winders with conic drums (fig.1) and crank mechanism, e.g. piston compressor (fig.3). In those mechanisms the moment of inertia depends on the sistance travelled by some mass. Figure 2 shows the moment of inertia versus angular distance plot of conic-drum winder, figure 4 shows the inertia versus distance plot of a crank mechanism. In this case the conditions of stable performance of the system depend not only on the slope of characteristics of motor and driven mechanism, but on an additional term as well (formula 19). The latter depends on the slope of inertia versus angular displacement characteristics. This additional term may be regarded constant with conic drum winders, where as with the crank mechanism it is represented by sine curve (formula 26), with periodically changing sign. In both cases this additional term may cause instability.