A/c train
Topic Author
Posts: 674
Joined: Sun Jun 10, 2001 7:57 am


Tue Mar 13, 2001 2:17 am

Are engine driven Hydraulic pumps mostly gear type pumps?
Posts: 1665
Joined: Mon Dec 20, 1999 3:16 am


Tue Mar 13, 2001 2:59 am

No, they're usually the multiple piston / "swash plate" type...as are most electrically driven pumps. The output is controlled by varying the angle of the plate and thus stroke of the pistons. The plate will move relative to the demand on the system. This way a pump can be running but if the demand is minimal, actually moving little fluid ( compared to a high demand situation ). The pump's purpose is really just to supply fluid _volume_...the pressure coming from the restrictions that the various user systems place on the system as a whole.
Posts: 129
Joined: Thu Dec 30, 1999 7:41 am


Mon Mar 19, 2001 11:11 pm

the pumps are running to constant pressure at their outlet. if more demand, the pressure tends to decrease, this makes the plate adjust providing for higher stroke of the pistons, thus retoring nominal pressure but at higher flow.
 Smile/happy/getting dizzy

Who is online

Users browsing this forum: Bambel, Calder, Dardania, longhauler and 22 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos