LRS Micro-g LaCoste FG5, Manual, Page: 16 / 149

Design: Components and Function
2
2.1.3.DRIVE MECHANISM
The drive mechanism (Figure 2-2) is a support structure inside the dropping
chamber on which the cart/drag-free chamber travels up and down, driven by a
DC servo motor.
2.1.4.SERVICE RING
The Service Ring (Figure 2-6 and Figure 2-7) is the base of the Dropping
Chamber. It provides connection and mounting for the following:
•
A bellows-type vacuum valve for the initial evacuation of the vacuum
system
•
A Ferrofluidic rotary vacuum feedthrough which connects the motor
shaft to the cart drive mechanism
•
A servo motor/rotary shaft encoder assembly which moves the cart and
senses its position
•
An electrical vacuum feedthrough which allows connection of the test
mass tracking electronics to the controller
•
An ion pump , mounted on a 2¾” Conflat flange, which maintains the
vacuum once the chamber has been evacuated by the roughing pump
•
Spare 2¾” Conflat and Mini-Conflat flanges are blanked off, and can be
used for additional vacuum accessories
Figure 2-6
. Side view of the service ring.
2-6