
2.HOW TO USE SERVO MOTORS SPECIFICATIONS FOR THE αiS/αi SERIES B-65262EN/03
- 32 -
Timing belt
A timing belt is used in the same cases as gear connection, but in
comparison, it has advantages such as low cost and reduced noise
during operation, etc. However, it is necessary to correctly understand
the characteristics of timing belts and use them appropriately to
maintain high precision.
Generally, the rigidity of timing belt is sufficiently higher than that of
other mechanical parts such as ball screw or bearing, so there is no
danger of inferiority of performance of control caused by reduction of
rigidity by using timing belt. When using a timing belt with a position
sensor on the motor shaft, there are cases where poor precision caused
by backlash of the belt tooth and pulley tooth, or elongation of belt
after a long time becomes problem, so consideration should be given
to whether these errors significantly affect precision. In case the
position sensor is mounted behind the timing belt (for example, on the
ball screw axis), a problem of precision does not occur.
Life of the timing belt largely varies according to mounting precision
and tension adjustment. Please refer to the manufacturer's Instruction
Manual for correct use.
Connection between the straight shaft and a connecting element
To use a straight shaft that has no key groove, connect the shaft with a
coupling using a span ring. Because the span ring connects elements
by the friction generated when the screw is tightened, it is free from
backlash and the concentration of stress. For this reason, the span ring
is highly reliable for connecting elements.
To assure sufficient transmission with the span ring, factors such as
the tightening torque of the screw, the size of the screw, the number
of screws, the clamping flange, and the rigidity of connecting
elements are important. Refer to the manufacturer's specifications
before using the span ring. When a coupling or gear is mounted using
the span ring, tighten the screws to remove a run-out of the coupling
or gear including the shaft.