gear pump(redirected from Annular gear pump)
gear pump[′gir ‚pəmp]
a rotary pump with gears as working members. Involute straight-cut, helical, or herringbone gears are ordinarily used. Such pumps are simple in design, compact, and reliable. Their output ranges from 0.25 to 40 cu m per hr at pressures up to 3 meganewtons per m2 (30 kg-force per cm2). Gear pumps are used mainly for circulating petroleum products in machine lubrication systems and in hydraulic drive mechanisms.