B-65382EN/02 HANDLING, DESIGN, AND ASSEMBLY 2.MECHANICAL DESIGN
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2.15 AXIS DESIGN WITH A LOW GRAVITY CENTER
For high-acceleration machines, load should be imposed uniformly on
the linear guide surface. For this purpose, such a design that the center
of the driving source or the motor is closer to the gravity center of a
moving object is desirable. Such a design is also expected to improve
efficiency.
If the gravity center is deviated in high-speed operation, machine
operation and precision may be adversely affected.
2.16 SCREWS FOR FIXING THE LINEAR MOTOR
A magnet plate has a powerful magnetic attraction force. When
magnetic screws are used, they are attracted abruptly to the magnet,
resulting in very inefficient workability. In such a case, use, for
example, nonmagnetic stainless screws. Such screws are not attracted
to the magnet, and therefore improve workability. In addition, use
nonmagnetic tools. Nonmagnetic tools are not attracted to the magnet,
so that workability and safety usually attainable can be maintained.
For securing a coil slider, ordinary magnetic screws may be used
because the coil slider itself does not exert magnetic attraction force.
When securing a coil slider, use those screws that are stronger than
stainless steel and have a strength equivalent to that of high tensile
steel.
When selecting any type of screw, consider the load and magnetic
attraction of the linear motor sufficiently. Tighten each screw securely
within the specified tightening torque. Control torque, and be careful
not to exceed the screw strength limit.
CAUTION
When securing a coil slider and magnet plate with
screws, be sure to use all screw holes and tighten
the screw securely. For a long-stroke axis, in
particular, a very large number of screws need to
be used with the magnet plate. Be sure not to omit
screws. Moreover, be sure not to secure a coil
slider and magnet plate only by using means other
than screws (for example, by using adhesive only).