Gear teeth profile ensures smooth flow

A new range of hydraulic pumps has been launched that benefits from a unique gear teeth profile that ensures smooth flow of viscous media. Dean Palmer reports A range of pumps has been launched which benefits from an improved design of integral gear section with an optimised teeth profile to ensure smooth and efficient flows for either free-flowing or highly viscous media. Johnson Pump's new 'TopGear' range of pumps has a simple, but effective operating principle that starts with the rotor and idler un-meshing, creating an under-pressure with the liquid entering the newly-created cavities. Liquid is transported in sealed pockets to the discharge side of the pump. The walls of the pump casing and the crescent create a seal that separates suction from the discharge side. The rotor and idler then mesh pushing the liquid into the discharge line. Pump capacities are from 0.5m3/h up to 125m3/h at pressures up to 20 bar. There are three main ranges available: the L-range for low viscosity; the G-range for general purpose liquids transfer; and the H-range for more demanding applications. The pumps also benefit from improved priming and low NPSHr, with maximised ports and ports above the centreline, optimum efficiency with axial rotor locking, adjustable clearances and hydraulic design. The simple cartridge design and front and back pull-out panels also ensure that downtime for maintenance is minimised. Small radial and axial clearances ensure reduced slip and optimised rotor and gear shape. The rotors are machined in one piece from steel bar. The pumps are suitable for petrochemicals, chemicals, paints and inks, resins and adhesives, pulp and paper and food processing. Options on the standard range include packed gland, single and double mechanical, lip and cartridge seals, heating and cooling jackets, and single and double safety relief valves.