PEC manufacture high performance Rotatory Gear Pumps that are positive displacement type having spur, helical or herring bone pair of gears. Gears are precision hobbed and press fitted and keyed to a drive shaft. The basic types of gears are: Internal Gear Pumps External Gear Pumps Foot Mounted Internal Gear Herringbone Gear http://www.pecindia.in/rotatory-gear-pumps.html