RU2085445C1 - Flying vehicle landing-gear retraction and extension drive - Google Patents

Abstract

FIELD: manufacture of new flying vehicles and modification of present-day flying vehicles. SUBSTANCE: drive includes control lever fitted in crew cabin and mechanical reduction gear mounted on landing-gear strut. Control lever is mechanically linked with input shaft of reduction gear. Drive is additionally provided with flat aerodynamic surface mounted on landing-gear strut between pivot shaft of strut and landing-gear wheel rotatably relative to landing-gear strut; output shaft of reduction gear is mechanically linked with this aerodynamic surface. EFFECT: enhanced reliability. 2 dwg

Description

 The invention relates to the field of drives for cleaning and landing gear of an aircraft and can be used to create new and modernize existing aircraft.

 Known drive cleaning and release the landing gear of the aircraft, containing a command lever mounted in the cockpit of the aircraft, and a mechanical gearbox mounted on the landing gear, and the command lever is mechanically connected to the output shaft of the gearbox (German patent N 665839, B 64 C 25/10 , 1938).

 A disadvantage of the known drive is the use of considerable muscular effort and the long time it takes for the pilot to release and clean the landing gear, which can distract the attention of the pilot and reduce the flight safety of the aircraft at the stages of landing and landing gear. Release and cleaning of the chassis is carried out by the muscular effort of the pilot applied to the command lever. In flight of an aircraft, inertial and aerodynamic forces occur on the struts and wheels of the landing gear, as well as frictional forces that prevent the landing gear from releasing and cleaning.

 The technical result of the invention is to reduce the muscular effort and time of their creation by the pilot in the process of releasing and cleaning the landing gear while maintaining a small mass of the drive for cleaning and releasing the landing gear.

 The specified technical result is achieved in that in the drive for cleaning and releasing the landing gear of the aircraft, comprising a command lever mounted in the cockpit of the aircraft, and a mechanical gearbox mounted on the landing gear, and the command lever is mechanically connected to the input shaft of the gearbox, an aerodynamic plane is additionally introduced the surface mounted on the landing gear between the axis of rotation of the strut and the chassis wheel with the possibility of rotation relative to the landing gear, and the output shaft of the gearbox is mechanically The ski is connected to this aerodynamic surface.

 In FIG. 1 shows the proposed drive when the landing position of the landing gear; in FIG. 2 proposed drive in the retracted position of the landing gear.

 The cleaning and landing gear drive (see FIG. 1) contains a command lever 1 mounted in the cockpit and mounted on a drive roller 2 mounted on axis 3 with the possibility of rotation relative to the aircraft body. The drive roller 2 is mechanically connected via a cable 4 to the driven roller 5, mounted on a shaft 6, which, through bearings 7, is mounted inside the axis 8 of the landing gear with rotation relative to axis 8, which is rotatably mounted in the aircraft’s body. A bevel gear 9 is fixed on the shaft 6, which is meshed with a bevel gear 10, mounted on the shaft 11, mounted by bearings 12 inside the rack 13 of the chassis with the possibility of rotation relative to the rack 13, attached to the axis 8. On the shaft 11 is also attached leash 14, which, through the pin 15 fixed thereon, is connected to the aerodynamic surface 16 mounted on the stand 13 with the possibility of rotation relative to it. On the rack 13, the chassis wheel 17 is also mounted rotatably relative to the rack 13. Gears 9 and 10 form a mechanical gearbox, the input shaft of which is shaft 6, and the output shaft is shaft 11.

где S,C $\genfrac{}{}{0ex}{}{\text{α}}{\text{у}}$ площадь аэродинамической поверхности 16 и производная по углу атаки коэффициента C_y подьемной силы поверхности 16;
ρ плотность воздуха;
V скорость летательного аппарата.The drive operates as follows. The position of the drive elements in the initial state with the released position of the rack 13 of the chassis is shown by solid lines (see figure 1). To clean the chassis command lever 1 is translated into the position shown by the dotted line (see figure 1). In this case, the driving roller 2 is rotated. Its rotation through the cable 4 is transmitted to the driven roller 5, shaft 6 and gear 9. At the same time, gear 10, shaft 11 and leash 14 are also rotated. Through pin 15, which enters the hole at the end of aerodynamic surface 16, this aerodynamic surface rotates relative to the strut 13 to the position shown by the dotted line in figure 1. In this case, the aerodynamic surface 16 becomes at an angle of attack relative to the velocity vector of the aircraft, as a result of which an aerodynamic force is created on the aerodynamic surface 16, defined by the expression

where s, c $\genfrac{}{}{0ex}{}{\text{α}}{\text{at}}$ the area of the aerodynamic surface 16 and the derivative with respect to the angle of attack of the coefficient C _{y of the} lifting force of the surface 16;
ρ air density;
V is the speed of the aircraft.

The force Y _g on shoulder 1 creates a moment M _g
M _g Y _g • 1 (2)
relative to the axis O _{x of} rotation of the axis 8 of the landing gear, under the action of which the landing gear 13 rotates in the direction of cleaning to the retracted position.

которая на плече 1 создает момент M_в
M_в Y_в • 1 (4)
относительно оси O_x вращения оси 8 стойки шасси. Под действием этого момента стойка 13 шасси поворачивается в сторону выпуска шасси до выпущенного положения стойки 13.The position of the drive element in the initial position of the landing gear is shown by solid lines (see figure 2). To release the chassis, the command lever 1 is translated into the position shown by the dotted line in figure 2. In this case, the driving roller 2, the driven roller 5, the shaft 6, the gear 9, the gear 10, the shaft 11 (see Fig. 1), the leash 14 and the aerodynamic surface 16, which as a result of rotation will take up the position shown by the dotted line, are rotated (see Fig. .2). In this case, the aerodynamic surface 16 will be in the air stream at an angle of attack a _in and the aerodynamic force Y _in

which on shoulder 1 creates moment M _in
M _to Y _to • 1 (4)
relative to the axis O _x rotation axis 8 of the landing gear. Under the influence of this moment, the rack 13 of the chassis rotates towards the release of the chassis to the released position of the rack 13.

To assess the operability of the cleaning and landing gear drive, the calculations were performed with the following initial data: the moment of inertia of the strut 13 with the wheel 17 and the aerodynamic surface 16 relative to the axis O _{x of} rotation of the axis 8 is I _x 13 kgm; the aerodynamic surface 16 has a square shape in plan with a side of 0.2 m; C $\genfrac{}{}{0ex}{}{\text{α}}{\text{at}}$ 1.5; ρ1.22 kgm ^-3 ; V = 108 mph ^-1 = 30 ms ^-1 ; l = 0.6 m; a _g = α _in = 0.3.
With these initial data on the basis of (1) and (3) received
Y _g = Y _in = Y = 1.5 • 4 • 10 ^-2 • 0.3 • 1.22 • • 9 • 10 ² • 0.5 = 9.9 H,
and based on (2) and (4)
M _g = M _in = M = 9.9 • 0.6 = 5.95 H _m .

где

угловое ускорение вращения стойки 13.The equation of motion of the rack 13 has the form

Where

angular acceleration of rotation of the rack 13.

Интегрированием уравнения (5) получаем изменение угла F_ст и угловой скорости

поворота стойки 13 с течением времени t:

Пусть для прихода стойки 13 в убранное положение необходим поворот этой стойки на 90^o от выпущенного положения. Тогда для уборки шасси требуется время t_n

и угловая скорость

стойки 13 в момент прихода ее в убранное положение составит

Проведенные расчеты показывают, что привод уборки и выпуска шасси при довольно небольших размерах аэродинамической поверхности 16 осуществляет уборку и выпуск шасси за сравнительно короткое время. Выбором соответствующего расстояния между осью вращения аэродинамической поверхности 16 относительно стойки 13 и точкой приложения аэродинамической силы Y, а также выбором длины командного рычага 1 можно обеспечить приемлемое усилие на командном рычаге 1 для его поворота при уборке и выпуске шасси. При этом коэффициент передачи от командного рычага 1 к аэродинамической поверхности 16 можно считать близким к 1 и значение потребного угла F_кр поворота командного рычага 1 будет примерно равно значению F_ап угла поворота аэродинамической поверхности 16. Если, как принималось выше в расчетах, F_ап=0,3, то F_кр=0,3 и при угловой скорости

вращения летчиком командного рычага 1, равной

54 град.c (с. 0,785с.^-1), время, которое затратит летчик на выполнение операции уборки или выпуска шасси, составит около 0,4 с. Таким образом, предлагаемый привод позволяет летчику выполнить уборку и выпуск шасси при создании им небольших мускульных усилий в течение непродолжительного времени, чем и достигается цель изобретения.

By integrating equation (5) we obtain a change in the angle F _article and the angular velocity

rotation of the rack 13 over time t:

Let for the arrival of the rack 13 in the retracted position, it is necessary to rotate this rack 90 ^o from the released position. Then it takes time t _n to clean the chassis

and angular velocity

rack 13 at the time of its arrival in the stowed position will be

The calculations show that the drive cleaning and landing gear with a fairly small size of the aerodynamic surface 16 performs cleaning and landing gear in a relatively short time. By choosing the appropriate distance between the axis of rotation of the aerodynamic surface 16 relative to the strut 13 and the point of application of the aerodynamic force Y, as well as by choosing the length of the command lever 1, it is possible to provide an acceptable force on the command lever 1 to rotate it when cleaning and releasing the chassis. In this case, the transmission coefficient from the command lever 1 to the aerodynamic surface 16 can be considered close to 1 and the value of the required angle F _{cr of} rotation of the command lever 1 will be approximately equal to the value of F _{ap the} angle of rotation of the aerodynamic surface 16. If, as was assumed above in the calculations, F _ap = 0.3, then F _cr = 0.3 and at angular velocity

rotation of the pilot command lever 1 equal to

54 deg.c (p. 0.785s. ^-1 ), the time that the pilot will spend on the operation of cleaning or releasing the chassis will be about 0.4 s. Thus, the proposed drive allows the pilot to clean and release the chassis while creating small muscular efforts for a short time, which achieves the purpose of the invention.

Claims (1)

 A drive for cleaning and releasing the landing gear of the aircraft, comprising a command lever mounted in the cockpit of the aircraft, and a mechanical gearbox mounted on the landing gear, the command lever being mechanically connected to the input shaft of the gearbox, characterized in that a flat aerodynamic surface is additionally inserted into it, mounted on a landing gear between the axis of rotation of the strut and the chassis wheel with the possibility of rotation relative to the landing gear, and the output shaft of the gearbox is mechanically connected to this aerodynamic surface.

Images