飞机起落架设计

《飞机起落架设计》由会员分享，可在线阅读，更多相关《飞机起落架设计（6页珍藏版）》请在装配图网上搜索。

1、Aircraft Landing Gear Layouts飞机起落架设计（中英文对照 图）发布人：圣才学习网 发布日期：20100625 14:36共292人浏览大中小Most aircraft today have three landing gea r.许多现代飞机使用三点式起落架.Two main landing gea r str uts located nea r the middle of the ai rcraft usually supp ort about 90% of the planes weight while a smaller nose strut supports

2、 the rest.重心附近的两个大的主轮，承担约90%的重量，小轮子承担余下部分。This layout is most often referred to as the ”t ricycle” landing gea r arr angementHoweve r, the re are nume rous othe r designs that have also been used ove r the yea rs, and each has its own advantages and disadvantages . Lets take a closer look at the var

3、ious undercarriage options available to enginee rs.目前的飞机以前三点起落架为主，让我们来回顾一下后三点起落架及其优缺点。（意译）Tail wheel or Tail dragger Gear后三点尾轮式与后三点尾橇式起落架Though the tr icycle arr angement may be most popula r today, that was not always the case. The tail wheel unde rcarr iage dominated aircraft design for the first

4、four decades of flight and is still widely used on many small piston engine planes.虽然前三点起落架比较普遍，但是在几十年前的飞机,及当今的许多小型飞机是使用后三点起落架的。The taild ragge r arr angement consists of two main gea r units located nea r the cente r of gravity （CG） that support the majority of the planes weight.后三点起落架，由两个在重心靠前位置的主

5、轮支持大部分的飞机重量。A much smalle r supp ort is also located at the rear of the fuselage such that the plane appea rs to drag its tail, hence the name.一个非常小的尾轮装置在机身，看上去这个小轮子是被拖着走,所以，英文Taildragger也因此而得名。This tail unit is usually a very small wheel but could even be a skid on a very simple design 它即可以是一个小尾轮，也

6、可以是一个尾橇。后三点起落架What makes this form of landing gea r most att ractive is its 引 mplicity.后三点起落架最吸引人的优点就是简洁。The gear are usually relatively lightweight , and the two main gear can also be easily encased in str eamlined fai rings to pr oduce low drag in flight.后三点起落架通常重量都比较轻。两支主轮子可以配置整流置用来减小飞行中的阻力。Anoth

7、e r potential advantage r esults from the fact that the plane is alr eady tilted to a large angle of attack as it r olls down the ru nway.另一个潜在的优点，是飞机在跑道滑行时，机翼已经有一个较大的迎角.This attitude helps to gene rate gr eate r lift and r educe the distance needed for takeoff or landing.合适的大迎角，有利于在较低的速度下产生足够的升力，以便

8、于减少起飞滑跑距离。This attitude is also an advantage on pr opelle r dr iven planes since it pr ovides a large clea rance between the pr opelle r tips and the gr ound. 对于牵引式螺旋桨飞机,机头向上抬起，使 螺旋桨不会接触跑道.(意译)Fur the rmore， taild ragge r planes are gene rally easie r for gro und per sonnel to maneuve r aro und in c

9、onfined spaces like a hanga r.同时，后三点起落架的飞机，更便于地勤人员把飞机拖到停机棚等窄小的空间里.Howeve r, the gr eatest liability of this landing gea r layout is its handling cha racte ristics.另一方面，后三点起落架也有一个最大的缺陷着陆时的操纵(handling cha racte ristics).This design is inhe rently unstable because the planes cente r of gr avity is loca

10、ted behind the two main gea r.造成此天生缺陷的原因，是因为两只主轮在重心的前面。If the plane is landing and one wheel touches down first， the plane has a tendency to vee r off in the di rection of that wheel.如果着陆时起落架只有一只主轮前触地，这时，飞机有向此轮子一边转弯倾向。This behavi or can cause the ai rcraft to turn in an inc reasingly tighte r gro un

11、d loop that may eventually r esult in scr aping a wingtip on the gro und, collapsing the gea ror vee ring off the ru nway.严重时，这种转弯的倾向(g round loop)将可能使翼尖触地、起落架受损、滑出跑道。Landing a taildragger can be difficult since the pilot must line up his approach very car efully while making constant r udde r adjus

12、tments to keep the plane on a str aight path until it comes to a stop.这就要求在飞机着陆触地前，需要使用方向舵修正自己的航线，使它能够笔直的滑翔直到安全触地。Many taild ragge r designs alleviate these handling pr oblems by fitting a tailwheel that can be locked instead of swiveling on a castor Locking the tailwheel helps keep the plane rollin

13、g in a str aight line du ring landing.使用尾橇，能减轻这种现象。（意译）前三点起落架与后三点起落架的安定性对比Anothe r disadvantage of the taild ragge r is poor pilot visibility du ring taxiing since he is for ced to pee r ove r a nose that is tilted upwa rd at a steep angle.后三点起落架的另一个缺点，许多飞机在地面滑跑，机头向上翘起时，会影响飞行员的视线。（意译）It is also ofte

14、n difficult to load or unload heavy car gos because of the steep slope of the cabin floor.对于货机，飞机的迎角不利于货物的装卸.Simila rly， pilots and passenge rs are for ced to walk uphill dur ing boa rding and downhill afte r arr ival.此问题，对于乘客来说，也是一样的道理。（意译）Many aircr aft also r ely on gr avity to br ing fuel from t

15、anks to the engine, and some planes have been known to have difficulty starting the engine because it is uphill from the fuel supply发动机抬起，有时也不利于供油，造成启动困难。道格拉斯DC3的后三点起落架Good examples of taild ragge r aircraft include the Spitfi re and DC 3 of Wor ld War II.后三点起落架的典型例子：喷火战斗机、道格拉斯DC 3.Tricycle or Nosew

16、heel Gear前三点起落架Now the most popular landing gear arrangemen上 the tricycle undercarriage includes two main gea r just aft of the cente r of gr avity and a smalle r auxilia ry gea r nea r the nose.前三点起落架，由两支在重心后的主轮，与一个在机头的辅助前轮组成。（意译）The main advantage of this layout is that it eliminates the gro und l

17、oop pr oblem of the taild ragge r.前三点起落架最大的优点是不会像后三点那样，着陆时容易打转。This arr angement is instead a stable design because of the location of the main gea r with r espect to the cente r of gr avity.这得益于主轮子在重心后部的设计。As a r esult, a pilot has more latitude to land safely even when he is not aligned with the r

18、u nway.这样，就算着陆时飞机没有对准跑道，飞行员还是有办法修正方向的。前三点起落架Fur the rmore， the tr icycle arr angement is gene rally less demanding on the pilot and is easie r to taxi and stee r.前三点起落架更容易操纵。（意译）The tr icycle gea r also offe rs much bette r visibility ove r the nose as well as a level cabin floor to ease passenge r

19、tr affic and cargo handling.水平的机身，使视界比较好，而且便于装货及乘客行走。A fur the r plus is that the ai rcraft is at a small angle of attack so that the thr ust of the engine is more par allel to the di rection of tr avel, allowing faste r accele ration during takeoff机翼的小迎角，螺旋桨在水平方向产生的力，有助于飞机更快获得速度（意译）In addition， the

20、 nosewheel makes it impossible for the plane to tip ove r on its nose du ring landing， as can sometimes happen on taild ragge rs.另外,由于前轮距重心较远，就不会出现后三点起落架容易发生的拿大顶”现象。（意译）The gr eatest dr awback to tricycle gea r is the gr eate r weight and drag inc urred by adding the large nosewheel str ut.前三点起落架最大的

21、缺点是，较重的重量及较大的阻力。（意译）Whe reas many taild ragge rs can afford to use non retr acting gea r with minimal impact on perfor mance， planes with nosewheels almost always r equi re retr action mechanisms to r educe dr ag.另一方面，固定式后三点起落架耐冲击性能较强。而前三点起落架，需要收放式以减小飞行时的阻力。Some planes with tr icycle gea r also have

22、 difficulty r otating the nose up dur ing takeoff because the main wheels are located so close to the elevator and the re may be insufficient control effectiveness. Similarly, the closeness to the rudder reduces its effectiveness in counte racting cr osswinds.前三点起落架影响舵效。（意译）Anothe r cr itical fact o

23、r when designing tr icycle gea r is to pr ope rly balance the load carr ied by the main gear versus the nosewheel . Too little load on the main wheels reduces their br aking effectiveness while too little on the nosewheel r educes its stee ring effectiveness. Car eful balancing of weight is also imp

24、 or tant to pr event the plane from tipping back on its tail while at r est on the gro und.前三点起落架对飞机重心的要求也比较高。747加油次序不当，造成机尾触地的危险。The re are many examples of aircr aft with tr icycle landing gear including the F16 and Cessna 172.F16与Cessna 172都是前三点起落架的经典案例。Summary总结Landing gea r ser ves three pr ima

25、 ry pur poses起落架的三个主要任务：to pr ovide a supp ort for the plane when at r est on the gro und,一、把飞机停放在地面。to pr ovide a stable chassis for taxiing or r olling dur ing takeoff and landing,二、起飞及着陆时提供稳定的支持。and to pr ovide a shock abs or bing system du ring landing.三、着陆时减震.Rega rdless, all of these tasks are

26、 seconda ry to the planes pr ima ry role as an efficient mode of tr avel thro ugh the air.飞机的飞行性能还是很重要的。（意译）To aircraft designe rs, landing gea r are nothing more than a necessa ry evil since planes are designed pr ima rily for the ir perfor mance in flight r athe r than on the gro und.飞机的飞行性能比在地面的性

27、能重要的多（意译）The re have even been attempts ove r the yea rs to eliminate landing gea r ent ir ely. The most ext reme case was a study done by the Royal Navy to see if a jet plane could make a belly landing on the deck of an aircraft carrier coated with a r ubbe rized sur face.有人尝试过不使用起落架，直接用机腹在航母甲板上着陆。

28、（意译）If successful， the method would eliminate the need for the very strong and heavy landing gear used on carrierbased aircraft. Unfortunately, the method proved impractical, but it shows the lengths some will go to while attempting to eliminate the need for landing gea r!很不幸，这个试验暂未完成成功.（意译）We have

29、seen that landing gea r come in many var ieties and each option has its own advantages and disadvantages.我们看到,有各种各样的起落架，每一种都有它自己的优缺点.Selecting the best arr angement for a given air craft is a tr ade off between these str engths and weaknesses as they apply to the env iro nment the plane is designed

30、for.实用中，需要根据飞机及外界环境，综合优缺点考虑来进行选择。As a result， designers try to select the simplest smallest, lightest, and least expensive solution possible to do the job while maintaining safety.在保障安全的前提下，最简单的、最小的、最轻的、最便宜的方案是比较好的选择。That is why most planes only have three landing gea r r athe r than four because fewe r gea r weigh less, require less structure aboard the plane take up less space when retracted and gene rate less dr ag.分析现在的飞机,就是按照上面的说法设计起落架的如:重量更轻、简洁的结构、更小的阻力、收放式。