Yaskawa SGDH Linear Sigma Series - Manual (Page 179)

7.1 Linear Servomotor Installation
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Make sure that hands or tools are not jammed or caught due to the attraction of the magnetic way when the coil assembly
approaches the end of the magnetic way. When the air gap between the coil assembly and the magnetic way is fixed, the
nonmagnetic sheet is not required. (Refer to the table of dimensions in step 1.)
3. Move the coil assembly back and forth several times over the magnetic way from end to end, making sure
that the coil assembly is not touching the magnetic way and that no foreign objects (such as magnetic par-
ticles) are present. Use a nonmagnetic (brass or stainless steel) gap gauge to check that the air gap
between the coil assembly and the magnetic way is even (estimated gap:
± 0.3 mm (0.012 in)).
(3) Magnetic Attraction
The linear servomotor is constructed of an opposing coil assembly and magnetic way. Therefore, magnetic attrac-
tion is offset when the air gap between the coil assembly and both magnetic ways is even.
However, achieving an even air gap is difficult due to the accuracy of the linear servomotor itself and the device,
and error in the assembly of the linear servomotor at installation. Consider the magnetic attraction values shown
in the following table when designing the device to account for the effect of magnetic attraction (calculated val-
ues).
* 1. Indicates an air gap value when one side is +0.3 mm (0.012 in) and the other side is −0.3 mm (−0.012
in) relative to the design values.
* 2. Indicates the magnetic attraction at maximum force.
INFO
Coil Assembly
Model
SGLTW-
Air gap
G1
∗1
in mm
(in)
Air gap
G2
∗1
in mm
(in)
Magnetic
attraction
F1
∗2
(N)
Magnetic
attraction
F2
∗2
(N)
Attraction
difference
Δ F
(N)
20A170A†
1.3
(0.05)
0.7
(0.03)
760 1030 270
20A320A† 1510 2040 530
20A460A† 2260 3050 790
35A170A†
1.3
(0.05)
0.7
(0.03)
1330 1800 470
35†170H†
35A320A†
2650 3570 920
35†320H†
35†460A†
4000 5400 1400
40†400B† 1.7
(0.07)
1.1
(0.04)
4700 5900 1200
40†600B† 7000 8700 1700
50†170H† 1.3
(0.05)
0.7
(0.03)
1990 2600 700
50†320H† 3750 5100 1350
80†400B† 1.7
(0.07)
1.1
(0.04)
9200 11400 2200
80†600B† 13600 16900 3300
Air gap
G1
Magnetic
attraction
F1
Coil assembly
Magnetic way Magnetic way
Magnetic
attraction
F2
Air gap
G2