Specialized Concentrated Focused
Machining Operations
「
35
」
2) Servo Motor
ratio
on
decelerati
Mechanical
equivalent
Pulse
pitch
Screw
resolution
Encoder
A
B
ratio
gear
Electronic
Electronic gear ratio: if a servo motor makes one circle per every 5000 pulse commands sent by the
system, setting electronic gear ratio of the servo motor can make the servo rotate twice with the same
amount of pulse commands (please refer to parameter setting of each servo brand).
Please see the servo motor label plate and then refer to the corresponding manual to confirm its encoder
resolution. A label plate of YASKAWA SGMSH type motor is as shown below, and the 4th character in
motor type is the serial encoder specification, so the resolution of this motor is 2
17
, i.e. 131072.
M o t o r T y p e
：
T Y P E S G M S H - 1 0 A C A 2 1
S i g n
S p e c .
R e m a r k
2
C
1 7 - b it a b s o lu t e
S t a n d a r d
T h e 4 t h c h a r a c t e r :
s e r i a l e n c o d e r s p e c .
( T h e 4 t h c h a r a c t e r )
S t a n d a r d
1 7 - b it in c r e m e n t a l
Fig. 4-4 Name plate of servo motor encoder resolution
For instance: (an example of YASKAWA) the screw pitch of a certain type machine is 5mm, with 17 bit
encoder resolution,
―0.0001mm/p‖ pulse equivalent and ―1:1‖ deceleration ratio.
17
202
2
131072
8192
1
1
203
5 / 0.0001
5 / 0.0001
3125
PN
Electronic gear ratio
PN
Pulse Equivalent of Rotary Axis
The pulse equivalent of rotary axis refers to the rotation degree of the axis clamping the workpiece per
pulse. The rotary degree of workpiece per revolution of motor is equal to screw pitch.
1) Stepping motor
360
P ulse equivalent
360
S ubdivision M echanical deceleration ratio
S tepping angle
2) Servo motor
B
Encoder resolution Pulse equivalent
Electronic gear ratio
Mechanical deceleration ratio
A
360
