
B-65382EN/02 HANDLING, DESIGN, AND ASSEMBLY 2.MECHANICAL DESIGN
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2.10.5 Checking the Normal Operation of Cooling Systems
When the linear motor is operated using forced cooling, abnormal
flow of a coolant may cause overheat or a burnout of the linear motor.
Therefore, it is necessary to prepare a system that always monitors the
cooling systems and stops the linear motor safely in case of an
abnormality.
When cooling piping is disconnected at some midpoint, it may take
some time until the cooling unit detects it. In the worst case, the motor
may burn out before the cooling unit detects a failure. In addition,
when, for example, cooling piping is disconnected near the motor, a
lot of coolant is applied to the motor, probably causing defective
insulation or other failures. So, the system is recommended to stop the
motor by always monitoring the cooling systems instead of waiting for
the cooling unit itself to detect a failure.
For example, as shown in the figure below, create a system that has a
sensor for monitoring the status returned to the cooling unit and stops
the linear motor using a PMC ladder or other program upon detection
of an abnormality. This method can stop the motor safely even when
the cooling unit itself fails or cooling piping is disconnected, unless an
abnormality occurs in the sensor.
Cooling unit
alarm
Coolant inlet
Coolant exit
Cooling unit
Cooling piping
Coolant
Coolant flowrate monitoring sensor
for detecting a decrease in coolant flowrate
mplifie
Motor
NOTE
1 Please prepare components such as the sensor
and PMC ladder required for this system by
yourself.
2 Overheat and a burnout of the motor cannot be
prevented only by this system. Be sure to make
thermostat wiring described earlier.