Siemens SINUMERIK 840D sl Function Manual page 360

M3: Coupled axes
8.4 Electronic gear (EG)
The setpoint of the following axis is calculated cyclically with the following logic equation:
n = n
c
with:
Quantities which influence the setpoint of workpiece axis C
The first addend of the above equation determines the speed ratio between workpiece table
and cutter, and thus the number of teeth of the workpiece.
The second addend effects the necessary additional rotation of the C axis as a function of the
axial feed motion of the cutter to produce the tooth inclination on helical teeth.
The third component also makes allowance for additional rotation of the C axis to compensate
for the tangential movement of the cutter in relation to the workpiece, thus ensuring that the
tool is equally stressed over its entire length.
Workpiece/tool parameter
The values z
operator or in the part program.
Differential constants
Differential constants u
geometry. These differential constants can be determined in user-specific cycles.
u = (sin β° / (m
dz
u = (cos γ° / (m
dy
with:
360
* (z / z ) + v * (u / z
b 0 2 z dz
n = Rotational speed of workpiece axis (C)
c
n = Rotational speed of milling spindle (B)
b
z = Number of gears of the hobbing machine
0
z = Number of teeth of the workpiece
2
v = Feed velocity of axial axis (Z)
z
v = Feed velocity of tangential axis (Y)
y
u = Axial differential constant
dz
u = Tangential differential constant
dy
, z , u , and u
0 2 dz dy
and u
dz
* π) ) * 360
n
* π ) ) * 360
n
m = Normal module (in mm)
n
β° = Incline angle of gear wheel
γ° = Pitch angle of hobbing machine
) + v * (u / z )
2 y dy 2
are workpiece- or tool-dependent and are specified by the NC
make allowance for the angle of workpiece teeth and for cutter
dy
[degrees/mm]
[degrees/mm]
Function Manual, 01/2015, 6FC5397-2BP40-5BA2
Special functions