Metering gear pump or segment, and metering gear pump assembly comprising a plurality of metering gear pumps or segments

A metering pump assembly, comprising:

• a plurality of metering pumps disposed within a serial array wherein each one of said plurality of metering pumps is disposed coaxially around a common longitudinal axis of said metering pump assembly and wherein each one of said plurality of metering pumps comprises at least one pump gear;
• a drive shaft assembly disposed coaxially with respect to said common longitudinal axis of said plurality of metering pumps, wherein said drive shaft assembly has a plurality of drive gears mounted thereon for respective engagement with said at least one pump gear of each one of said plurality of metering pumps so as to drive said at least one pump gear of each one of said plurality of metering pumps;
• a fluid inlet supply port disposed coaxially with respect to said drive shaft assembly and said common longitudinal axis of said plurality of metering pumps for supplying a fluid into said metering pump assembly along an annular flow path circumferentially surrounding and in contact with, said drive gear mounted upon said drive shaft and an external peripheral portion of said drive shaft assembly whereby the fluid is supplied to each one of said plurality of metering pumps;
• and
• a metered output fluid flow from each one of said plurality of metering pumps of said metering pump assembly.