Quantcast
Power-Driven Pumps

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
valve (B). Thus, a pressure stroke is produced with each stroke of the pump handle. Hand pumps are examined frequently for leakage, general condition, and efficiency in operation. To check the operation of a hand pump, the following procedure is recommended: 1. Connect a direct-reading hydraulic pressure gauge into the emergency hand pump pressure line. 2. Insert and lock the hand pump handle in the pump actuating socket. 3. Select an appropriate subsystem to operate, and place its selector valve in an operating position. 4. Actuate the hand pump handle until the unit being operated has completed its movement. Check the pressure gauge for a drop in system pressure. NOTE: Air in emergency systems will cause the pump handle to spring rapidly to the other end of the stroke. 5. If a pressure drop is indicated, check the system for leakage before removing the pump for repair or replacement. 6. Observe the hand pump handle for piston creep, which indicates that the pump should be removed for repair or replacement. Removal, replacement, and operational check of hand pumps should correspond to the procedures recommended in the specific MIM. Power-Driven Pumps As previously mentioned, power pumps are generally driven by the aircraft engine, but may also be electric-motor driven. Power pumps are classified according to the type of pumping action used, and may be either the gear type or piston type. Power pumps may be further classified as constant displacement or variable displacement. A constant displacement pump is one that displaces or delivers a constant fluid output for any rotational speed. For example, a pump might be designed to deliver 3 gallons of fluid per minute at a speed of 2,800 revolutions per minute. As long as it runs at that speed, it will continue to deliver at that rate, regardless of the pressure in the system. For this reason, when the constant displacement pump is used in a system, a pressure regulator or unloading valve must also be incorporated. The pressure regulator valve will maintain a set pressure in the system by diverting excess pump flow back to the reservoir. The unloading valve will divert all pump flow back to the reservoir when the preset system pressure is reached. This condition remains in effect until further demand is placed on the system. A variable displacement pump has a fluid output that varies to meet the demand of the system. For example, a pump might be designed to maintain system pressure at 3,000 psi by varying its fluid output from 0 to 7 gallons per minute. When this type of pump is used, no external pressure regulator or unloading valve is needed. This function is incorporated in the pump and controls the pumping action by maintaining a variable volume, at near constant pressure, to meet the hydraulic system demands. GEAR-TYPE PUMP.—A gear-type pump consists of two meshed gears that revolve in a housing (fig. 7- 14). The drive gear in the installation is turned by a drive shaft that engages an electric motor. The clearance between the gear teeth as they mesh and between the teeth and pump housing is very small. The inlet port is connected to the reservoir line, and the outlet port is connected to the pressure line. In the illustration, the drive gear is turning in a counterclockwise direction, and the driven (idle) gear is turning in a clockwise direction. As the teeth pass the inlet port, fluid is trapped between the teeth and the housing. This fluid is carried around the housing to the outlet port. As the teeth mesh again, the fluid Figure 7-14.—Gear-type power pump. 7-14



Aviation News
FAA Seeks Comments on Aircraft Emergency Operations
The FAA today issued a Federal Register Notice seeking public...
faa.gov
Overhaul Support Services to Improve Black Hawk Weapons System
Overhaul Support Services has received a $7.4 million firm-fixed-price contract...
aviationtoday.com
Search and Rescue: Extreme Maritime Challenges
S-70B Seahawk launches as a refueling probe is transferred while...
aviationtoday.com
Northrop Grumman Achieves B-2 Software Upgrade Milestone
[Avionics Today April 24, 2014] Northrop Grumman has completed the Preliminary...
aviationtoday.com
Rolls-Royce to Support V-22 Engines
Rolls-Royce has received $39 million to support AE 1107C engines...
aviationtoday.com
Rockwell Collins Reports on Project Missouri Radio Test
[Avionics Today April 23, 2014] Rockwell Collins released a statement about...
aviationtoday.com
Regional Scan: Latin America
Avianca Upgrades A320s With ROPS Flight display featuring the Airbus...
aviationtoday.com
Kestrel Makes sUAS Automation Progress
[Avionics Today April 23, 2014] Lockheed Martin's announced progress with its...
aviationtoday.com
Regional Scan: Middle East & Africa
Thales, Qatar to Develop OPV-A Thales, Qatar Air Force officials...
aviationtoday.com
Boeing Stands Out Among Lockheed, Northrop 1st Quarter Results
[Avionics Today April 23, 2014] Three of the world's largest aerospace...
aviationtoday.com
QF16: Unmanned Viper Takes Flight
  A pilotless F-16 during flight. Photo: Boeing The U.S....
aviationtoday.com
The Future of Unmanned Flight
Just five years ago, the idea of the futuristic aircraft...
aviationtoday.com
Sikorsky Flies Optionally Piloted Black Hawk
[Avionics Today April 22, 2014] Sikorsky Aircraft Corp. announced a successful...
aviationtoday.com
Time to Rethink UAS in the US
The Federal Aviation Administration’s (FAA) treatment of very small UAS...
aviationtoday.com
FAA Announces First UAS Test Site Operational
The North Dakota Department of Commerce is ready to start...
faa.gov
Mercury Systems to Provide UAS Processing Modules
[Avionics Today April 21, 2014] Mercury Systems announced a new $3.2...
aviationtoday.com
Airbus Corporate Foundation, JetBlue and Luftfahrt ohne Grenzen send humanitarian aid to Haiti
Ten tonnes of medicine, sheets and blankets shipped on JetBlue...
airbus.com
Northrop Grumman Opens Aircraft Integration Center
[Aviation Today April 16, 2014] Northrop Grumman announced its dedication of...
aviationtoday.com
L-3 TCAS System Selected for KC-46A
[Avionics Today April 18, 2014] Boeing has selected the T3CAS Integrated...
aviationtoday.com
F-35 to Make First U.K. Flight in July
[Avionics Today April 18, 2014] This summer's Royal International Air Tattoo show...
aviationtoday.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +