Overview Of The Hydraulic Path - Agilent Technologies InfinityLab LC Series User Manual

1 Introduction

Overview of the Hydraulic Path

Overview of the Hydraulic Path

The solvent from the bottle in the solvent cabinet enters the pump through an
active inlet valve. Each side of the binary pump comprises two substantially
identical pump units. Both pump units comprise a ball-screw drive and a pump
head with two sapphire pistons for reciprocating movement.
Inlet valve
Seal
Outlet valve
Piston
Figure 5
A servo-controlled variable reluctance motor drives the two ball-screw drives in
opposite directions. The gears for the ball-screw drives have different
circumferences (ratio 2:1) allowing the first piston to move at double the speed of
the second piston. The solvent enters the pump heads close to the bottom limit
and leaves it at its top. The outer diameter of the piston is smaller than the inner
diameter of the pump-head chamber allowing the solvent to fill the gap in
between. The first piston has a stroke volume in the range of 20 µL to 100 µL
depending on the flow rate. The microprocessor controls all flow rates in a range
InfinityLab LC Series 1260 Infinity II Binary Pump User Manual
Pump head
From solvent bottle
/degasser/SSV
To mixing chamber
15