YASKAWA SGD7C-***AMAA*** Product Manual page 633

Electronic Gear Settings
Use the following procedure to set the electronic gear.
1.
Check the following machine specifications.
Electronic Gear-related
Elements
• Gear ratio
• Ball screw pitch
• Pulley diameter, etc.
2.
Set fixed parameter No. 14 (Number of Pulses Per Encoder Rotation) to the amount of
change in the current count when the encoder rotates one revolution.
3.
Set the reference unit (the minimum unit of reference data used to move the load) by
setting fixed parameter No. 8 (Reference Unit Selection) and fixed parameter No. 9
(Number of Digits Below Decimal Point). Consider factors such as the machine specifi-
cations and positioning accuracy when you determine the reference unit.
If the reference unit is 1 μm, and 50,000 reference pulses are input, the workpiece will
Example
move 50,000 × 1 μm, or 50 mm.
4.
Use the reference unit to determine the travel distance per machine rotation, and then
set fixed parameter No. 10 (Travel Distance per Machine Rotation) to that travel dis-
tance.
Travel distance per load shaft revolution (reference units) =
Examples of machine configurations and the formulas used for them are given in the fol-
Example
lowing table.
Example machine
configuration
Formula for calculat-
ing the travel dis-
tance (reference
units) per load shaft
The following formula is used to calculate the travel distance (reference units) per load
Example
shaft rotation when the ball screw pitch is 5 mm and the reference unit is 0.001 mm.
5
= 5,000 (reference units)
0.001
Ball crew pitch
Gear ratio
Moving the Table with a Reference Unit of 0.001 mm.
Reference unit: 0.001 mm
Ball Screw
Load haft P
P: Pitch
P
Reference unit
12.8 Counter Function Module
12.8.2 Electronic Gear
Distance moved per rotation of the load shaft
Reference units
Rotary Table Belt and Pulley
Load haft
Load haft
60°
Reference unit
Reference unit
p
D
D
D: Pulley diameter
π
D
12
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