YASKAWA SGLGW User Manual page 48

(4) Others
 Magnetic Attraction between Moving Coil and Magnetic Way
Because the steel yoke is embedded in the moving coil to generate force, magnetic
attraction generates between the moving coil and the magnetic way. When the gap
between the moving coil and the magnetic way is uniform, the magnetic attraction on
the moving coil is offset.
A uniform gap is difficult to obtain, however, because it depends upon the precision
of the moving coil and the magnetic way products, deflection of the magnetic way,
precision of the equipment of the customer, and assembly error at the time of mount-
ing the motors. In case of non-uniform gap, the attraction shown in Table 2.3 is gen-
erated. When designing the equipment, take into account the attraction.
Moving Coil Model
SGLCW-
D16A085A
D16A115A
D16A145A
D20A100A
D20A135A
D20A170A
D25A125A
D25A170A
D25A215A
D32A165A
D32A225A
D32A285A

Indicates the gap of the machine when a dislocation of approximately 70% in comparison
to the designed value occurs.

Indicates the magnetic attraction at the time of maximum force.
Note: For the conditions other than those mentioned above, contact Yaskawa representative
separately.
The figure shown on the right is an example in which a
non-uniform gap occurs. Actually, magnetic attraction may
be generated and extended in all directions because of an
assembling error or other reasons.
www.dadehpardazan.ir 88594014-15
Table 2.3 Magnetic Attraction (calculated value)
Design Value of
Gap
(mm)
1.0
1.25
1.5
1.75
2.2 Linear Servomotor Installation
*1
Gap G1 Gap G2
(mm) (mm)
0.3 1.7
0.4 2.1
0.5 2.5
0.5 3.0
Moving coil
F2
F1
Magnetic way
Difference of
*1 Attraction
*2
F1-F2
(N)
20
30
40
25
38
50
50
75
100
80
120
160
G2
G1
2-25
2