Ewellix CAMT20, Installation, Operation And Maintenance Manual

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4.0 Structure a n d fun ctio n
4.5 Requirements for third party control units (manda-
tory in medical applications) (⮑ page 23) and chapter 4.6
Connections (⮑ page 23).
Gearbox
The gearbox contains the drive system that converts the
motor’s rotary motion into the translation motion of the
spindle.
This is done through the use of a worm gear and a lead-
screw. The worm shaft is directly integrated to the motor
and the worm wheel is integrated to the trapezoidal lead
screw nut.
A backup nut is located on the leadscrew to prevent the col-
lapse of the actuator in case of a failure of the screw nut.
The gearbox is pre-loaded to eliminate the axial clearance.
Protection tube
The main function of the protection tube is to provide an in-
terface for the rear attachment.
The length and the machining of the protection tube there-
fore vary depending on the selected attachment options.
The protection tube can be delivered as “short” or “long”.
When “short” (⮑ fig. 2), the protection tube is just long
enough to provide the space necessary for the attachment
regardless of the stroke. This option leaves the spindle un-
covered for all strokes from 100 mm and above.
Fig. 2
When “long” (⮑ fig. 3), the protection tube covers the entire
spindle. Even so, the rear side of the tube remains open to
leave access to the adjustable end-stop.
Fig. 3
WARNING
Safety hazard caused by interference
When using a short protction tube in combination with a long
leadscrew, the kinematic of the system should be carefully
studied to not get any interference between the back of the
spindle and the supporting pillar (or supporting structure in
general).
In worst case the interference could lead to a break or collapse
of the actuator and/or the support structure.
End position
The actuator stroke is limited by integrated end limit
switches that cut the power to the DC motor.
The end-stops are used to activate the limit switches via the
two flat springs that are attached on both sides of the main
housing and front cover. When the end-stops contact the flat
springs, the latter deflect and activate the limit switches that
are located on a PCB above the gearbox.