Class-Top Overload Durability; Wear Resistance Of Armature Coil; Dust-Proof Ball Bearing Thanks To The Labyrinth Construction - Hitachi G 18SR Technical Data And Service Manual

4-1. Class-top Overload Durability

The Models G 18SR, G 18SRU, G 23SR and G 23SRU provide excellent overload durability in common with the
current models. Figure 1 shows the comparison of overload durability when the stator coil temperature rise is
200ûK using the Model G 23SR as the reference. As is evident from this, the Models G 18SR, G 18SRU,
G 23SR and G 23SRU are superior to the competitors in overload durability.

4-2. Wear Resistance of Armature Coil

Both ends of the armature coil are sealed with heat-resistant adhesive in addition to varnish treatment to minimize
wear of the armature coil caused by dust.

4-3. Dust-proof Ball Bearing thanks to the Labyrinth Construction

The ball bearing retainers at both sides of the armature have a labyrinth construction to make the ball bearings
dust-proof.
Ball bearing (6301VVCM)
Armature shaft
100
Coating of heat-resistant adhesive
Bearing cover (A)
50 0
Fig. 1
Fig. 2
Labyrinth
Commutator
Fan
Fig. 3
--- 2 ---
G 18SR/G 23SR
G 18SRU/G 23SRU
C
B
Ball bearing
(6000VVCM)
Labyrinth
Housing
Dust seal
Bearing bushing