Patent ID: 8388321
Filing Date: 2013-03-05
Classification: F04B

Abstract:
1. A positive displacement pump apparatus for displacing a pumping fluid, the apparatus comprising: one or more pump chambers arranged in a pipe system for receiving the pumping fluid, the pipe system having at least one inlet which can be shut off by means of a valve, and at least one outlet which can be shut off by means of a valve; wherein the one or more pump chambers are connected via at least one intermediate fluid chamber with at least one displacement element, the at least one displacement element being arranged to alternately carry out a suction stroke and a displacement stroke during its movement so as to displace intermediate fluid in the at least one intermediate fluid chamber, which thereby increases and reduces, respectively, the volume of the one or more pump chambers; wherein at least one flexible separating element is provided at the one or more pump chambers to separate the intermediate fluid in the at least one intermediate fluid chamber from the pumping fluid, and wherein a force means is provided for applying force or energy to a side of said at least one displacement element at least during the displacement stroke, in such a manner that said force or energy counteracts the force exerted on the at least one displacement element by the intermediate fluid in the at least one intermediate fluid chamber, thereby reducing the overall force needed to carry out the at least one displacement stroke movement of the displacement element, wherein said force means uses a working fluid.