Table of Contents
Advertisement
• Maximum static torque at excitation
The maximum static torque at excitation represents the torque when the motor is
excited at the rated current. If the motor is combined with a dedicated driver, the
automatic current cutback function reduces the maximum static torque at excitation
to around 40%. (The specific value varies, depending on the motor standstill current
that is set.) Once started, the motor can be accelerated or operated at the maximum
static torque at excitation. However, the holding torque drops to around 40% while
the motor is at a standstill. Therefore, when selecting a motor consider the reduced
holding torque at motor standstill of around 40% of the maximum static torque at
excitation.
• Geared type motors
Allowable torque
Operate the motor by making sure the sum of the acceleration/deceleration torque at
the starting/stopping of the motor and the load (friction) torque doesn't exceed the
allowable torque. Operating the motor in excess of the allowable torque may result
in a damaged gear.
Allowable speed range
Operate the motor at speeds within the allowable range.
Operating the motor at a speed outside the allowable range may result in a shorter
gear life.
Backlash
The gear output shaft is subject to backlash of 1° to 2°. Backlash refers to the
looseness at the gear output shaft, as generated when the input side of the gear is
fixed. To reduce the effect of backlash, perform positioning operations from one
direction only either from the CW direction or the CCW direction.
Rotating direction of the gear output shaft
The relationship between the rotating direction of the motor shaft and that of the
gear output shaft changes as follows, depending on the gear type and gear ratio.
Gear ratio
3.6:1, 7.2:1, 9:1, 10:1
18:1, 36:1
Grease of geared motor
On rare occasions, a small amount of grease may ooze out from the geared motor. If
there is concern over possible environmental damage resulting from the leakage of
grease, check for grease stains during regular inspections. Alternatively, install an oil
pen or other device to prevent leakage from causing further damage. Oil leakage
may lead to problems in the customer's equipment or products.
Rotating direction
Same direction
Opposite direction
3 Precautions for use
−9−
Advertisement
Table of Contents
