Abstract: An improved gear pump having members with different hardnesses includes a housing defining an internal bore with inlet and outlet passageways. A head member includes a wall between the inlet and outlet passageways and extends toward a toothed rotor. A toothed idler gear meshes with the rotor. The head member and idler gear are made of materials having a hardness greater than that of the rotor material. In one embodiment the idler gear is made of ceramic material whereas the head member and rotor are made of cast iron, with the head member treated to have a hardness greater than that of the rotor.

Abstract: A machine for dispensing a plurality of ingredients includes stepped arrays of canisters providing a source of materials. The bottom ends of the canisters are generally coplanar, and are positioned immediately above a low profile drive train mounted on a tray. A drive train includes two spaced arrays of pumps with a motor providing a common drive for the pumps, mounted between the arrays. A valve tray is located above the canisters and includes a low profile dispense head, an array of tubing members arranged side-by-side in a common, generally horizontal plane, and an array of dispense valves attached at the back of the valve tray. The dispense valves are coupled to the pumps by pairs of fluid lines, so as to circulate materials between the pumps and dispense valves.