Patent ID: 6293756
Filing Date: 2001-09-25
Classification: F04B

Abstract:
A pump system for providing and maintaining a stable flow, comprising a first and a second pump unit, each pump unit comprisingi) two cylinders (2a, 2b) with a piston (3a, 3b) slidably arranged in each cylinder;ii) moving means (15a, 15b, 15c, 15d, 17, 19) for independently moving the pistons in said cylinders;iii) stepper motor means (22a, 22b, 22c, 22d) for causing said independent movement of each of said moving means (15a, 15b, 15c, 15d, 17, 19) to cause said movement of the pistons;iv) a control unit (21, 22) for dynamically changing the speed of movement of said pistons, in response to measurement data indicative of pressure changes in the system on the pressure side.