Comparisons In Torque Vs. Rotation Speed And Stator Coil Temperature Rise - Hitachi G 10SF3 Technical Data And Service Manual

6-2. Comparisons in Torque vs. Rotation Speed and Stator Coil Temperature Rise

Figure 1 shows comparisons of the rotation speed and the stator coil temperature rise between a competitive
model with respect to torque. Torque represents the magnitude of load, i.e., the amount of pressing force, cutting
depth and forward force in actual cutting jobs. This shows that a powerful motor is less likely to burn out because
it has both a minimum drop of rotation speed even at a greater torque and a lower stator coil temperature rise at
the same torque.
12,000
Rotation speed of spindle
10,000
8,000
6,000
4,000
2,000
0
0
Fig. 1 Comparisons in torque vs. rotation speed and stator coil temperature rise
Figure 1 indicates the followings:
The motor speed of the Model G 10SF3 is higher than that of C at the same torque. This means that the
working efficiency of the Model G 10SF3 is superior to C (Model G 10SF2 is also superior to C).
The stator coil temperature rise of the Model G 10SF3 is lower than the Model G 10SF2 thanks to the
improved cooling mechanism and it is equivalent to that of C. This means that the Model G 10SF3 has a burn-
resistant and tenacious motor.
C
HITACHI G 10SF2, G 10SF3
HITACHI G10SF2
C
Load
Torque range
--- 5 ---
X
X
X
HITACHI G 10SF3
Stator coil temp. rise
X: Burn-out point
600
500
400
300
200
100
0