Computer Drive Installation Instructions

12 Functional Descriptions 10.94

12.27.3 Switchover

In addition to variable increment evaluation, a gear ratio can be activated additionally via

parameters "Number of teeth, motor" and "Number of teeth, spindle". This is necessary when

gear ratios change as a result of gear changes (with indirect actual value sensing).

Gear ratios, numbers of teeth, paths

The gear ratio specifies the speed ratio between the drive and output ends:

n1 zs

R = ––– = –––

n2 zm

n1 = Drive speed

n2 = Output speed

zs = Output (spindle) number of teeth

zm = Drive (spindle) number of teeth

The ratio between the numbers of teeth (can be directly entered in new machine data) is

always inversely proportional to the ratio between the speeds.

The path on the workpiece side is thus calculated as follows:

xt = xs * h

xt = xg * h * –––

xt =Workpiece path

xs =Spindle path

xg =Motor path

h =Spindle pitch

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SINUMERIK 840C (IA)