WO1997047520A1

WO1997047520A1 - Device for bringing an aircrafts wheels to ground speed before landing, then for cooling the brake disks after landing

Info

Publication number: WO1997047520A1
Application number: PCT/FR1997/000953
Authority: WO
Inventors: Jacques-Francis Patte; Xavier Delaporte; Marie-Pierre Bertinet
Original assignee: Patte Jacques Francis; Xavier Delaporte; Bertinet Marie Pierre
Priority date: 1996-06-10
Filing date: 1997-06-02
Publication date: 1997-12-18
Also published as: FR2749559B1; FR2749559A1

Abstract

The invention discloses a device for bringing an aircrafts wheels to ground speed before landing, then for cooling the brake disks after landing. It consists of brass pipes (7) attached on the sliding tube (3) and terminated by wind nozzles (12) and cooling nozzles (25) on which are fixed electrovalves (20 and 21) opening the passage for compressed air. This device located on a bogie wheel rim (9) is designed first to start the wheel rotating before landing and subsequently to cool the overheated brake disks (23) at the time of landing. The compressed air is provided by reserve gas cylinders supplied by the 14?th or 15th¿ stage gas off-take valve of the engine high pressure compressor. Ten minutes before descent, the empty cylinders are charged to 30 kg pressure with compressed air on the pilot's command. The electrovalves on the reserve cylinder are automatically operated as soon as the undercarriage is locked; then the electrovalves (20) on the delivery spider (11) are automatically operated by an altitude sensor set to 2000 feet above ground to start rotating the wheels. Then a temperature sensor set at 50° (22) actuates the electrovalves (21) for cooling the brakes (23) from the moment braking starts until the plane comes to a complete stop. The device is particularly designed to avoid tyre deformation or even bursting at touchdown during landing and then to cool down and ventilate the overheated brake disks at landing and during acceleration-stop manoeuvres.

Description

TITLE OF THE INVENTION

DEVICE FOR BRINGING THE WHEELS OF AN AIRCRAFT TO GROUND SPEED BEFORE LANDING

THEN TO COOL THE BRAKE DISCS AFTER LANDING

DESCRIPTION

The present invention relates to a device for automatically bringing the wheels of a

airplane at ground speed two minutes before landing, and second, a system of

cooling of the brake discs on landing by the same process

This device is called L S A P (Landing Safety by Aircooled Process)

Trademark

At present large aircraft have an approach speed of 280 to 330 km / hour

depending on the outside temperature, the weight of the plane and the height of the terrain

The inertia of the wheels causes a rough touch of the tires on the bitumen during the landing

and therefore quickly causes wear, deformation like "cutlet" or

even the bursting of the tires, risking a departure from the trajectory

Likewise, there is significant fatigue in the structure of the train legs.

At present, landing maneuvers result in significant overheating of the

brakes and we know that airplanes cannot take off within an hour if the brakes fail

are not at a certain safety temperature for re-entry of trains

SUBSTITUTE SHEET (RULE 261 The device according to the invention makes it possible to considerably reduce these deteriorations by

creating a rotational movement of the wheels before landing and reduces the

brake disc cooling time, so the time intervals between the

landings and takeoffs will be shorter, with greater safety due

less warming.

The movement is the result of the application of compressed air on small cavities

located on the rim and fixed in honeycomb. The brake cooling process at

the landing is also the result of the application of compressed air. This compressed air from

compressed air cylinders are taken from the high compressor draw-off valve

reactor pressure. Depending on the reactor models, compressed air with 30 pressure legs

will be taken from the draw valve on the 14th or 15th stage of the high compressor

pressure and will be routed through a brass pipe 2.5 cm in diameter to the

200 liter cylinders required per reactor and per bogie.

These bottles will be placed in the luggage compartment near the bogies, in corners

lost so as not to penalize the volume of the hold The compressed air is cooled beforehand by the radiators supplied by the cold wind from the

Fan of the reactor. It is then routed through brass pipes having 2.5 cm of

diameter towards the center of the wheel, hence the three brass pipes of a delivery spider

distribute the compressed air over the cells by blower nozzles.

These nozzles are protected by a sealing shell which also reduces hissing. The

precise orientation of the blower nozzles determines the optimization of the force

Each bogie will have this system and the necessary energy will come from the reactor.

By way of example, using this device, tests have been carried out on a

75cm in diameter and a weight of 40 kgs. With a compressed air pressure of 10 kgs, it

a speed of 180 km / hour was obtained in 1 minute. On a 1.20 m diameter wheel

and weighing 200 kg, the wheel will reach a speed of around 300 km / hour with a

30 kg pressure in two minutes.

The energy is dispensed to the maximum at the beginning of the rotation, then the inertia enters

relationship ; two minutes are necessary for the rotation of the wheel, it remains

about 1 minute at speed without energy (but energy can be maintained if

necessary). It is necessary to couple a speedometer on a bogie wheel with a computer

flow opening already existing on the aircraft, to obtain the same speed on the wheel as

the ground speed of the aircraft.

A non-return valve will be placed at the inlet of each compressed air cylinder.

The cylinders will be placed empty at the departure of the plane in order to secure the cruise and

loaded at 30 kgs of compressed air pressure, 10 mins before the descent of the aircraft at

when the reactors are still at 75% of their power.

This maneuver controlled by the pilot by setting the LSAP switch to "On"

give the order to draw compressed air from the high pressure compressor of the reactor

and bring it to the reserve bottle

When the cylinder is full, the drain valve system of the

high pressure compressor, will resume its initial function.

An opening solenoid valve will be mounted on the other side of the compressed air cylinder

and will be ordered automatically as soon as the trains lock for

landing, thus the compressed air will be able to supply the delivery spider. The automatic contact control for starting wheel rotation is

produced by an altimetric probe set at 2000 feet / ground in final. So the

compressed air opening solenoid valves will direct compressed air to the air cells

the rim ; the solenoid valves will then be cut to 20 feet / ground

Knowing that :

- Two minutes are necessary to obtain the desired speed.

- The time interval between the height of 2000 feet / floor and the touchdown on the

track is two minutes losing 900 feet / minute.

- The speed is maintained by a computer coupled with the exact ground speed of

approach in short-final, and then cut by a second altimetric probe set

at 20 feet / floor.

This device is operational to obtain a rotation of the front wheels

landing in the allotted time; hissing noise not exceeding one minute is

considerably absorbed by the sealing shell.

When the pressure of the reserve cylinders is lower than that delivered by the

high pressure compressor of the reactor, it will take over to maintain the flow

and the pressure to the delivery spider. In a second step, the opening solenoid valves will be used to cool the

brake discs. As soon as these reach a certain heating temperature,

the opening of the solenoid spider valves will direct the compressed air to the nozzles

between the rims and the top of the brake discs.

The operation will be done automatically by a temperature probe set at 50 ° Celsius

(106 ° Fahrenheit).

This heat detecting probe can be doubled by bogie as a safety measure,

one on the front left brake of the bogie, and the other on the right rear brake.

As soon as the procedure is started, the cooling of the brakes is maintained throughout

along the journey, from the start of braking to the complete stop of the airplane at the terminal, the air

tablet providing additional ventilation as the discs spin.

If necessary, the cooling system will be maintained in the parking lot by the reactor

auxiliary (A.P.U) producing compressed air taken from the high compressor

pressure, and cooled beforehand This will avoid deploying the old B O A system.

cooling, or the sudden cooling of the brakes by the water jets emitted by the

firefighters This compressed air cooling system will be all the more appreciable in the event of

accelerate-stop maneuver (take off aborted), the brake discs then being reddened

by optimum heat; then the pilot will put the LSAP on "On".

The captain will carry out the entire procedure by simply pressing

"On" of the L.S.A.P.switch before the descent, and will stop it by putting the L.S.A.P.

on "Off" before leaving the plane at the parking lot.

The dashboard will therefore include compressed air pressure gauges,

reserve cylinders, and three green indicators of the opening of the solenoid valves: one for the

cylinders, one for rotating the wheels, one for cooling the

brake discs.

A wheel speedometer before landing will also be placed next to the tell-tale

green for rotating the wheels.

This device therefore allows both, at first, the rotation of the wheels

before landing, and in a second step, the cooling of the brake discs

after landing by reducing the risk of bursting tires and the risk

linked to the rapid overheating of the brake discs. The accompanying drawings illustrate the invention.

- fig. 1 represents a bogie beam provided with the invention,

- fig. 2 represents a detail of the bogie with the device,

- fig. 3 represents a side view of the bogie and of the device,

- fig. 4 represents a detail of the wheel fitted with the device,

- fig. 5 shows an enlargement of the high concave rim of the inner rim with the

device,

- fig. 6 represents the drawing off of the compressed air on the high pressure compressor of the

reactor.

With reference to these drawings, a distinction is made on the bogie beam (1) of FIG. 1, the wheel

(4), the brass pipes (7), fixed along the train barrel (2), the sliding tube (3) the

inner rim of the rim (9) in which the honeycombs (10) fixed are fixed

bee. We also distinguish the connection hoses (13) from the air hoses

compressed (7) which bring compressed air to the three arms of the delivery spider (11),

these bringing compressed air through blower nozzles (12) protected by a

sealing shell (8), towards the cells (10), the delivery spider (11) is fixed on the

fixed brake block (14) located on the wheel hub (15). Fig. 2 shows a detail of the bogie beam (1) with the brass pipes (7) fixed on

along the sliding tube (3) by fasteners (24). These pipes (7) supply the compressed air

towards the three arms of the delivery spider (11) terminated by blower nozzles (12) and

cooling nozzles (25).

The opening solenoid valves (20) for the rotation of the wheels, and the

opening solenoid valves (21) for cooling the brakes (23), are fixed on the

brass pipes (7).

A distinction is also made between the brake heating temperature sensor (22) and the

cooling nozzles (25) supplying compressed air to the brake discs (23).

Fig. 3 shows a side view of the bogie beam (1) with the pipes (7) and their

fixings (24) fixed on the fixed brake block (14).

The three arms of the delivery spider (11) are terminated by the blower nozzles (12)

protected by a sealing shell (8) directed on the cells (10) fixed on the

high concave rim of the inner rim (9), and are also terminated by the nozzles

cooling (25) directed on the brake discs (23).

There are the opening solenoid valves (20 and 21), the temperature probes (22). Fig. 4 shows the wheel (4) provided with the device with on the one hand, the three arms of

the delivery spider (11) which brings compressed air through blower nozzles (12)

controlled by opening solenoid valves (20) to the cells (10) fixed on the

rim flange (9) and the sealing shell (8) fixed on the arm of the delivery spider

(11) by fasteners (26).

On the other hand, it shows the three arms of the delivery spider (11) which bring the air

compressed by cooling nozzles (25) controlled by solenoid valves

opening (21) to the brake discs (23).

The superheat temperature sensor (22) is fixed to the fixed brake block (14).

We can see the direction of the wheel (5).

Fig. 5 shows an enlargement of the high concave rim of the inner rim (9) of

the wheel (4).

We can see the direction of the wheel (5), the detail of the cells (10) fixed in honeycomb

These cells are 1 cm in diameter and 1.5 cm deep. They are set at 30 °

perpendicular to the rim flange (9) one behind the other. The alveoli (10) are

end in diamond point (6) which will follow the direction of rotation (5) of the wheel (4) The rim of the inner rim is 4 cm wide and 1 cm deep at its center.

The three brass arms of the delivery spider (11) transport the compressed air to

blower nozzles (12) protected by a sealing shell (8) 14cm long and

6cm wide, shaped like a half funnel to maintain compressed air and reduce

hissing. This sealing shell (8) is fixed on the end of the spider's arm

debtor (11), above the blower nozzles (12) by fasteners (26).

Fig. 6 shows the plan of the energy source, namely, the compressed air coming from the

high pressure compressor of the reactor (17). The air is cooled in the radiator (19) by

the wind of the Fan (18) before accessing the withdrawal valve (16) from where it will be routed by

the brass pipes 10 (7) to the bogies (1).

This device according to the invention allowing the wheels of a front airplane to rotate

the landing and cooling of the brake discs is therefore particularly intended

aeronautical constructions.

Claims

1 °) Device for automatically bringing the wheels of an airplane at first

at ground speed in two minutes before landing, and then allow

the cooling of the brake discs after landing, characterized in that

comprises cells (10) fixed in honeycomb, having 1 cm in diameter and 1.5 cm in

depth.

These cells (10) end in a diamond point (6) which follow the direction of rotation

of the wheel (5) and are fixed at 30 ° perpendicular to the high concave rim of the rim

interior (9), this having 4 cm of width and a depth in its center of I cm. So

cell device (10) is applied during the descent phase of the aircraft, a

compressed air pressure of 30 kgs. This compressed air from the draw-off valve (16) of the

high pressure compressor of the reactor (17) is automatically routed to the

cells (10) by brass pipes (7) 2.5 cm in diameter and projected onto the

alveoli (10) by the three brass arms of a delivery spider (11) terminated by

blower nozzles (12) protected by a sealing shell (8) of about 14cm

long and 6cm wide, in the shape of a half funnel to keep the compressed air This device is further characterized in that it includes nozzles

cooling (25) also terminating the three arms of the delivery spider (11) and

directed towards the brake discs (23).

The delivery spider (11) transports the compressed air coming from reserve cylinders of

200 liters, supplied by the withdrawal valve (16) from the 14th or 15th stage of the

high pressure compressor of the reactor (17) according to the models

2 °) Device according to claim 1 characterized in that the brass pipes (7) having

2.5 cm in diameter and bringing the compressed air from the high pressure compressor of the

reactor (17) to the three brass arms of the delivery spider (11), are fixed along

landing gear barrel tubes (2) and characterized in that the joints between

the successive brass pipes (7) are provided by connection hoses

(13), and characterized in that the three arms of the delivery spider (11) are fixed on the

fixed brake block (14) located on the wheel hub (15) by fasteners (24)

3 °) Device according to claim 1, characterized in that the air sampling

compressed will be on the 14th or 15th stage of the high pressure compressor

reactor (17) and that the compressed air cooled beforehand by the radiator (19) supplied by

the fan wind (18) will be conveyed by a brass pipe (7) 2.5 cm in diameter

up to compressed air reserve cylinders 4 °) Device according to claims 1 and 3, characterized in that the cylinders of

compressed air reserve of 200 liters capacity will be placed empty on takeoff and

loaded at a compressed air pressure of 30 kgs, 10 minutes before the descent and

characterized in that a non-return valve and opening solenoid valves will be

placed on each reserve cylinder

5 °) Device according to claims 1 and 4, characterized in that the solenoid valves

fixed on the compressed air reserve cylinders, are

automatically controlled as soon as the trains lock for landing.

6 °) Device according to claim 1, characterized in that the opening solenoid valves

(20) fixed on the delivery spider (11) to bring the compressed air from the

reserve to the cells (10) for the rotation of the wheels, are controlled by a probe

altimeter set to 2000 feet above ground before landing and cut by a second

altimeter probe set to 20 feet / ground

7 °) Device according to claim 1, characterized in that the opening solenoid valves

(21) fixed on the delivery spider (11) to bring the compressed air from the

reserve to brake discs (23) to cool them, are controlled

automatically by a temperature probe set to 50 ° Celsius (106 ° Fahrenheit)

(22) 8 °) Device according to claims 6 and 7, characterized in that the three brass arms

of the delivery spider (1 1) fixed on the fixed brake block (14) located on the hub of the

wheel (15), first distribute the compressed air from the air reserve cylinders

compressed from the high pressure compressor of the reactor (17) by nozzles

blower (12) protected by a sealing shell (8) in the form of a half funnel

6cm wide and 14cm long, attached to the end of the delivery spider's arm (1 1)

exactly on the cells (10) terminating in a diamond point (6) to optimize the

force of compressed air. These three arms of the delivery spider (11) then distribute the air

compressed by cooling nozzles (25) directed precisely on the discs of

brakes (23).

9 °) Device according to claim 1, characterized in that it allows the compressed air

from the high pressure compressor of the reactor (17) and brought to the cells (10) by the

brass pipes (7) on pilot's command, produced in 1 minute on a fitted wheel

of the device, 75cm in diameter, and weighing 40 kgs, a speed of 180 km / hour

with a compressed air pressure of 10 kg, and characterized in that an air pressure

30 kg tablet from the high pressure compressor of the reactor (17) should

produce on a wheel with a diameter of 1.20 m and a weight of 200 kg, a speed

about 300 km / hour in 2 mins before the plane lands. The device is characterized in that the automatic apparatus placed in the cockpit

allows the captain to monitor the wheel rotation maneuver

two minutes before landing, corresponding to the time taken to pass from 2000

feet / ground to 20 feet / ground losing 900 feet / minute.

10 °) Device according to claims 1 and 9, characterized in that the operation

fully automatic controlled by the pilot will require on the dashboard,

compressed air pressure gauges for reserve cylinders and three green indicators

opening times of the solenoid valves: one for the reserve cylinders, one for the

wheel rotation 2 mins before landing; this witness will be located near a counter

wheel speed; and a green light for cooling the brakes after

landing.