Toothed-Lobed Gear Pump

Abstract

Toothed gears and lobed gears intermesh to create large volume pockets in gear sets of a given size. The pockets are larger than the pockets that exist in current tooth or lobe pumps and provide the benefit of a pump that better handles shear sensitive liquids. Preferably, the profiles of the teeth and of the lobes are involute-shaped to provide rolling contact and a fixed pressure angle between the teeth and lobes during engagement. The toothed gears and lobe gears improve upon standard spur and helical gear designs by omitting alternate teeth on the standard toothed gears and filling in corresponding gaps on the mating standard lobed gears. Additional tooth and lobed gear rotors may be added in tandem as additional pairs of gears to the shafts and circumferentially offset to provide driving tooth engagement between at least one pair of the toothed and lobed rotors at every point around the rotational circumference of the rotors. This spur gear or helical gear configuration eliminates the need for separate driving / synchronizing gears.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of Invention[0002]This invention relates generally to gear pumps used for liquids, and more particularly, to positive displacement gear pumps that emulate characteristics of lobe pumps.[0003]2. Description of Related Art[0004]Typical spur gear pumps used for pumping hydraulic fluids generally use a drive gear and an idler gear that mesh proximate inlet and outlet openings of the pump. As the drive and idler gears rotate, hydraulic fluid fills the gaps between adjacent spur teeth and is transferred from the inlet through an intermediate transition zone to the outlet. Each of the rotors has a plurality of radially extending, circumferentially-spaced spur teeth with recesses between the teeth. The teeth on each rotor intermesh with the teeth of the other rotor in sealing contact with the recesses of rotors therebetween. The drive gear and idler gear are mounted for rotation on spaced parallel axis with the gears or rotors typically enclosed in ...

AI Technical Summary

Benefits of technology

The invention is a pump with a gearbox that includes spur toothed gears and lobed gears. The gearbox is located in the pump's internal cavity and has a drive shaft and an idler shaft. The spur toothed gears are mounted on the drive shaft and the lobed gears are mounted on the idler shaft. The gears are designed to have continuously rolling contact and a fixed pressure angle during the driving engagement. The gearbox can be hydraulically isolated from the fluid using a partition wall and there are also radial vanes to seal the slip paths between the gears. The technical effect of the invention is to provide a more efficient and reliable pump with improved performance and reliability.

Problems solved by technology

However, spur pumps subject the spurs to fluid milling action that produces high shearing stress and high pressures.

This milling action is detrimental to shear sensitive liquids, such as delicate food substances (e.g., salsa, relish, mayonnaise, pasta sauce, soup).

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