6.1 Motors
6-5
Installation
6
(2) Belt Coupling
• Check that the motor shaft is parallel to the machinery shaft and that the line connecting the centers of the
pulleys and the shafts are at right angles to each other. If the angularity of the belt is improper, the belt will
vibrate or slip.
• The radial load imposed on the motor shaft edge must not exceed the permissible value specified in
3.1.4
Tolerance Radial Loads.
If an excessive radial load is imposed on the motor shaft, the motor bearings will
be adversely affected and the service life of the bearings will be decreased.
• Be sure that no axial load is imposed on the motor shaft.
• Check that the angle of contact of the belt and pulley will be 140
°
or more, or otherwise the belt may slip.
Belt Installation
(3) Gear Coupling
Check that the motor shaft is parallel to the machinery shaft and that the centers of the gears are engaged prop-
erly. Refer to
3.1.5 Motor Total Indicator Readings
for the precision of the peripheral parts connecting to the
motor shaft. The gears may grate if they do not engage properly.
Be sure that no axial load is imposed on the motor shaft.
(4) Mounting a Pulley or Gear to the Motor Shaft
When mounting a pulley or gear to the motor shaft, consider the mounting balance of the motor. The dynamic
balance of the motor is kept with a half key (for motors with a keyway), which is a half as thick as the key (T)
specified in the motor shaft dimensional drawing. The motor rotates at high speed and a little imbalance in the
mechanism may cause the motor to vibrate.
d
C
Belt
β
If C is 1,000 mm or less, d < 1 mm.
If C is more than 1,000 mm, d/C < 1/1000.
β
< 1/3°
Angle of contact
φ
>
140°
Machinery shaft
C
Motor shaft
φ