Precautions for use
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3
Precautions for use
This section covers limitations and requirements the user should consider when using the
LAS
series.
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Conduct the insulation resistance measurement or withstand voltage test separately on the lineard
motor and the driver.
Conducting the insulation resistance measurement or withstand voltage test with the lineard motor and driver
connected may result in injury or damage to equipment.
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Operate the motor at or below the maximum thrust force.
If the motor is operated while receiving a load beyond the maximum thrust force, the rack tooth surface or pinion
may be damaged. Therefore, always operate the lineard motor under a load not exceeding the maximum thrust.
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Do not apply an overhung load in excess of the specified permissible limit.
If the motor is operated continuously under an overhang load exceeding the permissible limit, the rack bushings may
be worn quickly or even damaged. Always keep the overhang load to the permissible limit or below.
Even if the overhang load is kept to the permissible limit or below, repeated operation of the lineard motor will still
cause the rack bushings to wear. To suppress rack bush wear, install a guide, etc., to reduce the overhang load or
rotational torque.
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Do not stop the rack by means of contact.
Never allow the moving rack to contact a hard object. The shock may damage the rack tooth surface, pinion and/or
gear.
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Reversing the rack
Be sure to reverse the lineard motor before either end of the rack enters the rack bushing. The rack operates properly
when being supported by the rack bushings on both sides of the rack case.
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Installing sensors
A desired rack travel amount can be specified accurately using pulse signals. However, also install sensors to detect
the home of the equipment and the rack end and process sensor signals on the controller side.
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Positioning direction
Stop the motor always from the same direction, as it will suppress the negative impact of rack and pinion backlash
and consequently improve the stopping accuracy.
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Lubricating the rack
Do not wipe grease off the rack surface or the tooth surface meshing with the pinion. Grease is pre-charged in the
rack case before shipment. If grease is wiped off, the rack and pinion life will become shorter. Always keep the rack
surface and tooth surface properly greased during operation.
If the rack is used in a lift device or at a high ambient temperature, grease may drip. If dripping grease becomes a
concern, place an oil pan underneath the rack.
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Operate the lineard motor with a surface temperature of the motor not exceeding 100 °C (212 °F).
The driver has an overheat-protection function, but the lineard motor has no such feature. The lineard motor case’s
surface temperature may exceed 100 °C (212 °F) under certain conditions (ambient temperature, operating speed,
duty cycle, etc.). Keeping the surface temperature of the motor casing below 100 °C (212 °F) will also maximize the life
of the motor bearings (ball bearings).
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Use an electromagnetic brake type for an application involving vertical travel.
For a lifter or any other lift device, use a lineard motor with an electromagnetic brake to hold the load and rack in
position. Always wait for the lineard motor to stop first, and then use the electromagnetic brake to hold the rack. Do
not use the electromagnetic brake for braking/stop operation. If used in such application, the brake hub of the
electromagnetic brake will wear quickly and the braking force will drop.
Since the electromagnetic brake is of the non-excitation type, it can also be used to hold the load in position upon the
occurrence of a power failure. However, this is not a secure means of holding the load. Do not use the electromagnetic
brake as a safety brake.
When the driver-protection function is triggered, the lineard motor stops as the current is turned off. The user must
set a controller sequence that will cut off the power to the electromagnetic brake and hold the load in position upon
detecting an ALARM output.
