
B–65152E/03
4. NOTES ON INSTALLATION
BCATLTLON EOT TFC α
27
CAUTION
(b) When the pulley is shorter than the key
When the pulley is shorter than the key, M
4
and M
5
in the full key imbalance section
may cause an imbalance. To satisfy the following equations, drill hole D
3
in advance:
π(D
3
/2)
2
H
3
ρR
3
=M
4
r
4
+M
5
r
5
D
3
: Diameter of the correction hole (cm)
H
3
: Depth of the correction hole (cm)
ρ : Specific gravity of the pulley (kgf/cm
3
)
R
3
: Distance from the center line to the correction hole (cm)
M
4
and M
5
: Weight of the key in section M
4
or M
5
(kgf)
(For the calculation, assume the
specific gravity to be 7.8 x 10
–3
kgf/cm
3
.)
r
4
and r
5
: Distance from the center line to M
4
or M
5
(cm)
Pulley, gear, or coupling
Full key
Section J–J
Magnified view
of section K
T/2 (Thickness of the half key)
T (Thickness of the full key)
Output shaft
NOTE
1 The same correction method is used for the gear, coupling, and so on as well as the pulley.
2 This correction is not required for a motor having no key.
3 When a motor is to be used at a speed higher than 4500 min
–1
, the use of a motor with
no key is recommended.
4 This correction does not result in the fully balanced status.
If correction is still required, perform correction (c).