
B-65222EN/03 HANDLING, DESIGN, AND ASSEMBLY 2.MECHANICAL DESIGN
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2.12 PROTECTION AGAINST DUST AND WATER
If magnetic dust such as metallic dust is located near a magnet plate,
the dust may be attracted to the magnet plate. In particular, dust larger
than the air gap between the coil slider and magnet plate is caught
between the gap, resulting in a failure. In order to remove dust that
builds up on the magnet plate, it is strongly recommended that a
scraper be installed. Moreover, if the motor is exposed to coolant
ceaselessly, the insulation of the motor can degrade. Consider a
structure that can minimize the penetration of coolant.
Usually, the penetration of foreign matter is prevented using a bellows
cover or telescopic cover. In addition, increasing the internal pressure
by air purge operation is very effective.
Besides coolant penetrating into the motor from the outside,
condensation may occur on the motor because of excessive cooling or
excessively high humidity. If condensation lasts for a long time, the
insulation of the motor can degrade. In such a case, take anti-
condensation measures such as reviewing the cooling condition and
blowing dry air to the motor.
The penetration of foreign matter may not be prevented by a dust and
waterproof cover or by air purge operation. In particular, an axis
installed horizontally allows more metallic dust or coolant to
penetrate. Moreover, for a high-speed moving axis, the securing of
sealing performance tends to be difficult. In such a case, review the
installation location of a linear motor axis. For example, keep a linear
motor axis away from the machining spot as much as possible, or
mount a linear motor axis on the top of the machine. These measures
are very effective.
In any case, the penetration of dust and coolant cannot be prevented
completely. So, be sure to conduct periodic maintenance (including
cleaning).
For reference information, a typical axis structure is shown below.
Linear guide
Dust cover
Coil slider
Scraper
Linear encoder
Magnet
late
Table
Machine base