Hospira LifeCare XL Series, Техническое и сервисное руководство

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4.3 MECHANICAL OVERVIEW
Technical Service Manual 4 - 19 430-00587-008 (Rev. 2/05)
4.3.2.1
MOTOR AND VALVE ASSEMBLIES
The mechanism assembly pumping action is controlled by three stepper motors. The first
stepper motor, in conjunction with an associated valve assembly, activates the primary
or secondary valve of the cassette, depending on the command. The second stepper motor
alternately opens and closes the inlet and outlet valve to control fluid delivery through the
cassette pumping chamber. A third stepper motor controls plunger movement.
4.3.2.2
PRIMARY/SECONDARY VALVE SUBSYSTEM
The primary/secondary valve subsystem includes a motor designed to rotate a cam
(see Figure 4-3, Mechanism Valve Pins and Sensor Locations) . When the cam is positioned
at the top dead center (home position), both valves are closed. Clockwise rotation (when
viewed from the motor side) from the home position opens the primary valve, while the
secondary valve remains closed. Counterclockwise rotation opens the secondary valve,
while the primary valve remains closed.
The primary/secondary valve subsystem consists of a stepper motor with attached cam
and integral cam flag, primary and secondary rockers and valve pins, and a pin detector
assembly. The cam flag passes through an interrupter module as it rotates with the cam.
Valve home position is determined by this cam flag/interrupter module combination
through predetermined factory calibration data. During operation, if the cam flag passes
through the interrupter module at the incorrect time sequence, a motor phase loss is
detected.
The rocker is the connecting link between the cam and the valve pin.
The primary/secondary valve pins each have a series of interrupters that are optically
detected by the pin detector assembly to assure proper valve pin movement.