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3) Excellent overload durability
The Models S 15SA and S 18SA provide excellent overload durability thanks to the improved cooling fan and
cooling air passage design as well as the high-power motor.
Overload durability is defined as the amount of thrust force required to raise the stator coil temperature by 200
K, and the ratio of these models to similar products C-1 and C-2 is indicated in Table 2. Comparing these data,
the Models S 15SA and S 18SA prove to have the excellent overload durability against C-1 and C-2.
Table 2 Comparison of overload durability
Maker
HITACHI
C-1 / C-2
Model
S 15SA / S 18SA
Overload durability ratio
1.2
1
4) New dust seal
Newly-designed dust seals are adopted in the bearing chamber on the commutator side. This ensures better
dust-resistance of the ball bearing in comparison with C-1 and C-2. The key features of the new dust seal are
as follows.
(1) Width is increased to 6.5 mm (C: 2 mm)
(2) 2-step side construction is provided and each step has labyrinth grooves.
Fig. 2
Labyrinth grooves
Labyrinth grooves
2 mm
6.5 mm
C-1 / C-2
HITACHI
S 15SA / S 18SA
Summary of Contents for S 15SA
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