โ Scribed by O'Hanlon, John F.
No coin nor oath required. For personal study only.
In this chapter we review the operation of five low vacuum pumps (the rotary vane and piston, scroll, screw and diaphragm pump), and two medium vacuum pumps (the lobe or Roots pump and the claw pump). Vane and piston pumps are widely used for backing high vacuum pumps and for initial chamber evacuation. Lobe blowers are used with piston or vane pumps to rough large systems, to back large pumps, and to pump large quantities of gas in plasma processing systems. Screw, scroll, and diaphragm pumps are used in oil-fiee applications, and the claw pump is particularly well suited for pumping particulate-laden atmospheres.
ROTARY VANE PUMP
๐ SIMILAR VOLUMES
Organic fluids are used in rotary vane, piston, screw, scroll, lobe, turbomolecular, and diffusion pumps. In a rotary vane or piston pump fluids provide a vacuum seal between the moving surfaces and lubricate and cool the low-speed bearings and sliding surfaces. Screw, scroll, lobe, and turbomolecul
Pumping speed is a quantity few of us measure. We are usually content with published data; however, we should know how speed is measured, so that we can meaningfully interpret data. Pumping speed is measured by established, standard techniques. Recommended practices have been improved; however, much