5.1.2 Electronic Gear - YASKAWA SVC User Manual

5.1 Motion Parameters

5.1.2 Electronic Gear

The following examples show the settings for a ball screw and rotary table.
Example Parameter Settings for a Ball Screw
• Machine specifications: The ball screw axis rotates 5 times for every 7 rotations of the motor
axis. (Refer to the following figure.)
• Reference unit: 0.001 mm
Motor
To move the workpiece 0.001 mm for 1 reference unit input under the above conditions, i.e., for
1 reference unit to equal 1 output unit, make the following settings for fixed parameters No. 6,
No. 8, and No. 9.
• No. 6 (Travel Distance per Machine Rotation): 6 mm/0.001 mm = 6,000 (reference units)
• No. 8 (Servomotor Gear Ratio Term): m = 7
• No. 9 (Machine Gear Ratio Term): n = 5
Important
Example Parameter Settings for a Rotary Table
• Machine specifications: The rotary table axis rotates 10 times for every 30 rotations of the
motor axis. (Refer to the following figure.)
• Reference unit: 0.1°
To rotate the rotary table 0.1° for 1 reference unit input under the above conditions, i.e., for 1
reference unit to equal 1 output unit, make the following settings for fixed parameters No. 6,
No. 8, and No. 9.
• No. 6 (Travel Distance per Machine Rotation): 360°/0.1° = 3,600 (reference units)
• No. 8 (Servomotor Gear Ratio Term): m = 30
• No. 9 (Machine Gear Ratio Term): n = 10
5-4
m = 7 rotations
Workpiece
P (pitch) = 6 mm per rotation
n = 5 rotations
To use the electronic gear by setting the motion parameters, set the electronic gear ratio in the
SERVOPACK parameters to 1:1. However, to use a 24-bit resolution encoder, refer to the follow-
ing section and set the electronic gear ratio in the SERVOPACK parameters.
5.4 Absolute Encoders with 24-Bit Resolution on page 5-53
Workpiece (rotary table)
360° per rotation
n = 10 rotations
m = 30 rotations
Motor
Ball screw