VARIABLE FLOW CONTROL USING LINEAR PUMPS

摘要

Variable (10) and fixed ratio 100 dispensing systems are disclosed. Each pump (12) is powered by a DC motor (14) spinning a gear pump (16) which is immersed in a hydraulic power pack (18). The power pack 18 output feeds a hydraulic linear motor (20) where its direction is controlled by a two output reversing valve (22). The hydraulic linear motor (20) drives one or two material pumps (24) which are mechanically attached to the hydraulic pump (12). The pressure and/or flow outputs of the material pumps (24) are controlled by altering the torque output of the DC motor (14), using a custom designed motor control module (MCM) (26). The MCM (26) uses a linear position sensor (28) and a pressure transducer (30) installed at the output of the material pump (24) as primary process variables (or feedbacks) for the pump (24). The system not dependant upon expensive flow meters for controlling the pump output.