Reciprocating Piston Vacuum Pump

Rotary piston vacuum pumps are based on the rotational action of an eccentric cam — not a piston producing a reciprocating action in a linear direction. Like linear piston pumps, it is the piston in this pump which is exposed to the material being removed from the work chamber. 

Vacuum breaker, 291 Vacuum pump, 9 Vacuum service, 10 ejectors in, 11 liquid pi.ston, 9 liquid piston, 130 sliding vane, 10 Valve design, 62 Valve loss, reciprocating, 62 Valve unloader, 81 Valve velocity, 62 Valves... 

The most used mechanical vacuum pumps or compressors are reciprocating, liquid-ring, rotary-vane, rotary blower, rotary piston, and diaphragm. 

Vacuum pumps reciprocating piston type decrease the pressure to 1 Torr rotary piston down to 0.001 Torr, two-iobe rotary down to 0.0001 Torr steam jet ejectors, one stage down to 100 Torr, three stage down to 1 Torr, five stage down to 0.05 Torr. 

In 1840 a hydrauHc power network, which involved large reciprocating pumps that were driven by steam engines, suppHed fluid power to London. However, concurrent technology in steam (qv) turbines and the electric generators outmoded such networks until hydrauHc systems were improved with the use of rotary pumps and oil. The rotary piston pump marked the transition from use of water to oil as the hydrauHc fluid (4). The use of vacuum-distilled, refined mineral oils were instmmental in the success of rotary axial piston pumps and motors such as the Waterbury variable speed gear... 

Huff [23] found that reciprocating and rotary piston pumps were the most economical mechanical systems for their range of application. Obviously, the economic discussions are dependent on the vacuum expected and the local utility costs, plus the cost of maintenance. 

---