Three Spindle Screw Pump

"TUSHACO" - a leading name in the field of Positive Displacement Rotary pumps since 1968 introduced for the first time in India the concept of "Three Screw Pumps" already in 1970's. Foreseeing the growing demand for totally reliable fuel and lube oil pumps for Thermal and Hydel Power Plants, Fertilizer, Chemical and Steel Projects a beginning was made by importing critical components and building pumps locally. Over decades, thousands Three Screw pumps have been manufactured and delivered. Valuable experience gained and modern manufacturing and testing facilities established under joint collaboration from world-renowned German company. 

Today TUSHACO is undisputed leader not only in Three Screw pump technology but equally in the other types - namely Twin Screw, Single Screw/ Progressing Cavity - as well as the conventional types like Shuttle Block, Internal Gear, External Gear, Trochoidal and Vane types. This unique position, combined with years of Application Engineering expertise and knowledge of Process Engineering requirements offers direct benefit to customers by the right choice of the pump design selection for almost any given duty parameters.

TUSHACO pumps are on the OEM list of practically all major plant and equipment manufacturers, consulting organizations and has met with approvals from third party inspection agencies - national and international.

Reliable performance of thousands of TUSHACO Three Screw pumps in India and overseas - over decades is the silent testimonial of the hard and dedicated efforts behind this success.

Working Principle

TUSHACO Three Screw pumps employ just three screw elements - one power screw and two idler screws running in the three precision bores in the housing or liner. The screws are so profiled that they form a liquid tight seal between the thread. As the screws rotate, pockets/ cavities are formed where liquid gets trapped and conveyed from one end of the infinite stroke. This results in smooth, pulsation free flow with extremely low noise and vibration levels, almost impossible to be achieved by any other design of positive displacement or other types.

The power rotor does not drive the idlers as commonly believed. The hydraulic forces acting on screw flanks turn the idlers torquelessly thus reducing the friction. The idlers simply roll over the root diameter of idler dia.reduce the unit pressure, centralize the power rotor and absorb the radial loads. A balance piston integrally machined on power rotor takes care of axial thrusts.

While in operation, the screws are in hydrodynamic balance on film lubrication and do not require any additional bearings. The one ball bearing often used is only for axial positioning of rotor and safer operation of mechanical seals. Small rotor dimensions enable the pump to be operated at high speeds directly coupled 3000 or 3600 RPM motors or other prime movers. Such unique design and features has demonstrated excellent reliability with pumps in operation continuously non-stop for decades together without replacement of any components or maintenance on clean fluids.