CN217270522U

CN217270522U - Cascade type thrust reverser and thrust reverser cascade

Info

Publication number: CN217270522U
Application number: CN202221425960.9U
Authority: CN
Inventors: 辛立波; 赵佳佳; 韩聪聪
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2022-06-08
Filing date: 2022-06-08
Publication date: 2022-08-23
Anticipated expiration: 2032-06-08

Abstract

The utility model provides a reverse thrust cascade, can provide the reverse thrust of a plurality of directions, includes fixed frame and multirow blade, still includes connecting axle and transmission, and each row of blade is installed respectively on the connecting axle, the connecting axle is in the last rotation of fixed frame sets up, and transmission connects each respectively the connecting axle for receive drive arrangement's power take off, in order to drive each the connecting axle synchronous rotation. A cascade thrust reverser comprises the cascade thrust blade.

Description

Cascade type reverse thrust device and reverse thrust cascade

Technical Field

The utility model relates to a cascade formula thrust reverser and thrust reversal cascade.

Background

Thrust reversal of turbofan engines requires thrust reversal to change the direction of the engine thrust, thereby reducing the glide distance of the aircraft upon landing. In the landing process of the airplane, the airflow passing through the reverse thrust device is reversed, and the deceleration of the airplane is realized. The thrust reverser devices commonly used on an aircraft mainly have three types according to the working principle: grab bucket type, baffle gate type and cascade type.

When a deflecting door of the grab bucket type thrust reverser is in a closed position, the effect of the deflecting door is equivalent to that of a part of a spray pipe; when the air jet is in the working position, the baffle door blocks the airflow channel of the jet pipe, so that the airflow is guided by the blade grids and then is ejected forwards, and therefore reverse thrust is obtained.

The baffle door type thrust reverser consists of a plurality of groups of pivoting doors and driving mechanisms which are arranged on the outer wall of the engine nacelle along the circumferential direction of the engine. When the bypass valve works, the baffle doors rotate around the pivot, and the inner side part of each group of doors plays the role of a choke valve to block the airflow of the outer bypass; the outer part plays a directional flow guiding role in exhausting and generates reverse thrust. The baffle door type thrust reverser is suitable for turbofan engines, the thrust is about 40% of the static thrust of the engine, and the baffle door type thrust reverser is applied to A320, A330 and A340 passenger planes.

The cascade type thrust reverser consists of a cascade, a movable cover and a choke valve. When the air flow guiding device works, the movable fairing moves backwards (or the cover is opened) to expose the blade cascade, and the flow blocking door blocks the backward flowing outer duct air flow so as to lead the backward flowing outer duct air flow to be deflected and guided to flow out through the blade cascade. The cascade reverse thrust device mainly works in an outer duct airflow and is usually arranged in the middle of an engine nacelle below a wing, and the reverse thrust airflow is ejected forwards at the front edge of the wing. Compared with a baffle door type reverse thrust device, the device has the advantages of smarter and more compact structure and more stable reverse thrust. The cascade thrust reverser is only suitable for a turbofan engine, and the reverse thrust of the cascade thrust reverser can be up to 35 percent of the maximum thrust of the engine. The cascade type thrust reverser is mainly used for a turbofan engine with a large bypass ratio, and is commonly applied to large airplanes such as a boeing 747 and the like. The applicant has disclosed thrust reverser cascades or cascade thrust devices respectively in the patent specification with chinese patent publication (publication) No. CN 112881026A, CN 210119353U, CN 113865838A, CN 212563479U.

The size and direction of the reverse thrust of the cascade reverse thrust device can not be actively controlled, the application range is limited, and the reverse thrust function can not be fully exerted. Accidental opening in reverse thrust air can lead to serious catastrophic accidents because the direction of reverse thrust cannot be changed.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a thrust reversal cascade, it can provide the thrust reversal of a plurality of directions.

Another object of the utility model is to provide a cascade thrust device, it includes aforementioned reverse thrust cascade, can improve the security of aircraft when reverse thrust device is opened in the air accident.

According to the utility model discloses an aspect, the blade cascade of pushing back includes fixed frame and multirow blade, and it still includes connecting axle and transmission, and each row of blade is installed respectively on the connecting axle, the connecting axle is in rotate the setting on the fixed frame, transmission connects respectively each the connecting axle for receive drive arrangement's power take off, in order to drive each the connecting axle rotates in step.

In one or more embodiments, the transmission device comprises a rack and a plurality of gears, the plurality of gears and the plurality of connecting shafts are respectively connected, the rack is meshed with the plurality of gears, and the rack or one of the gears is used for receiving the power output of the driving device.

In one or more embodiments, the transmission device includes a worm and a plurality of worm wheels, the worm wheels and the worm are respectively connected, the worm is meshed with the worm wheels, and the worm or one of the worm wheels is used for receiving the power output of the driving device.

In one or more embodiments, the fixing frame includes an outer frame in which the plurality of rows of blades are disposed, and a plurality of lateral fixing plates that are orthogonal to the respective rows of blades and support the connecting shafts, the lateral fixing plates being rotatably supported by the outer frame, the lateral fixing plates passing through gaps of the respective rows of blades.

In one or more embodiments, a guide member is disposed on the transverse fixing plate and/or the outer frame, a guide fitting member is disposed on the blade, and the guide member and the guide fitting member are slidably fitted to guide the blade to rotate around the connecting shaft.

In one or more embodiments, the plurality of rows of blades are configured to be rotationally switched between at least three positions including a cascade zero reverse thrust position, a cascade reverse thrust position, and a cascade positive thrust position.

According to the utility model discloses a on the other hand, cascade thrust device is including enclosing into a plurality of reverse thrust cascades of annular, and it still includes drive arrangement, reverse thrust cascades is arbitrary reverse thrust cascades, drive arrangement output power respectively extremely transmission.

In one or more embodiments, the driving device is a multi-position cylinder, each thrust reverser cascade corresponds to one driving device, the transmission device comprises a rack and a plurality of gears, the plurality of gears and the plurality of connecting shafts are connected respectively, the rack is meshed with the plurality of gears, and the rack is used for receiving the power output of the driving device.

In one or more embodiments, the driving device is a motor, each reverse thrust cascade corresponds to one driving device, the transmission device includes a worm and a plurality of worm wheels, the worm wheels are connected with the worms respectively, the worm is meshed with the worm wheels, and the worm or one of the worm wheels is used for receiving power output of the driving device.

Because each row of blades are respectively arranged on the connecting shafts, the connecting shafts are rotatably arranged on the fixed frame, and the transmission devices are respectively connected with each connecting shaft to drive each connecting shaft to synchronously rotate, the reverse thrust can be continuously adjusted or adjusted in multiple gears, so that the application range of the reverse thrust function is expanded; (2) when the air reverse thrust is opened accidentally, the air reverse thrust can be adjusted to be the forward thrust and the reverse thrust, so that the safety is improved, and serious catastrophic accidents are avoided; (3) the reverse thrust is adjusted in the landing process of the airplane, and the maneuverability of the airplane is improved.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a cascade thrust reverser in a stowed state.

FIG. 2 is a schematic view of a cascade thrust reverser in a deployed state.

FIG. 3 is a schematic view of a thrust reverser cascade in a zero thrust condition.

FIG. 4 is a schematic view of a thrust reversal cascade in a thrust reversal state.

FIG. 5 is a schematic view of a thrust reverser cascade in a forward thrust condition.

Detailed Description

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Fig. 1 shows the retracted state of the thrust reverser, in which the thrust reverser cascade 3 is covered by the moving cowl 1, the chokers 4 do not obstruct the air flow, and the air flow is guided through the bypass between the moving cowl 1 and the core nacelle cowl 2.

Fig. 2 shows the reverse thrust device in an unfolded state, at this time, the moving cover 1 moves backwards to expose the reverse thrust blade cascade 3, and the choke valve 4 blocks the backward flowing bypass airflow to make the backward flowing bypass airflow turn and flow out through the blade cascade.

The thrust reverser guides the airflow through the thrust reverser cascade 3, thereby achieving the thrust reverser effect. The angle of the thrust reverser cascade 3 is designed to be adjustable in the following embodiments, so that the switching between the positive thrust state, the zero thrust state and the negative thrust state can be realized.

As shown in fig. 3, the thrust reverser cascade 3 comprises a fixed frame and a plurality of rows of vanes 72. The fixed frame includes an outer frame 72 and a plurality of transverse fixing plates 74, the outer frame 72 includes four circumferential side walls defining a hollow shape, and the transverse fixing plates 74 are spaced apart from each other at the outer frame 72 for enhancing rigidity of the fixed frame. The thrust reverser cascade 3 also comprises a plurality of connecting shafts 71 and transmission means. The transmission comprises a plurality of gear wheels 31 and a rack 32. Each connecting shaft 71 is provided with a gear 31. Each row of blades 72 is fixed to a connecting shaft 71, and the connecting shafts 71 straddle the two side walls of the outer frame 72 and are rotatably disposed. The gear 31 drives the connecting shaft 71 to rotate, and then drives each row of blades 72 to perform rotation adjustment. The rack 32 is used as a linkage mechanism to drive the gears 31 to rotate synchronously, and further drive the rows of blades 73 to rotate. The lateral fixing plates 74 are orthogonal to the respective rows of blades 73 and support the connecting shaft 71, thereby enhancing the rigidity of the connecting shaft 71, and the lateral fixing plates 74 pass through the slits of the respective rows of blades 73, thus allowing the blades 73 to rotate. In another embodiment, the transverse fixing plate 74 is optional in case the frame stiffness and the connecting shaft stiffness are ensured by the choice of material. In a further embodiment, the transverse fixing plate 74 and/or the outer frame 72 are provided with guiding elements, and correspondingly the vanes 73 are provided with guiding mating elements, the guiding elements and the guiding mating elements are in sliding fit to guide the vanes to rotate around the connecting shaft, so as to ensure that the rotating position and the rotating direction of the vanes 73 are accurate and obtain the expected reverse thrust, and the guiding elements can be arc-shaped grooves, and the guiding mating elements are correspondingly guiding pins.

In another embodiment, the transmission of the thrust reverser cascade can be replaced by other mechanisms, for example a worm gear, i.e. the rack 32 is replaced by a worm, each worm 31 is replaced by a worm wheel, and the worm gear itself has a self-locking function, thus ensuring the desired adjustment of the vanes 73.

The cascade thrust reverser comprises a plurality of thrust reverser cascades as shown in fig. 3, which are arranged in a ring around the engine axis. With continued reference to fig. 3, the cascade thrust reverser also comprises a drive 6, the drive 6 outputting power to the transmission of the thrust reverser cascade. In one embodiment, the drive means 6 is an electric motor, which drives a worm or worm wheel of the transmission. In another embodiment, the drive means 6 is a multi-position cylinder which drives a rack of the transmission means. In yet another embodiment, the driving device 6 is a reduction motor with a worm gear reduction mechanism, which drives the worm or worm wheel or gear of the transmission device through its power output shaft. In another embodiment, the driving device 6 is a multi-position cylinder which transmits thrust to the transmission of each thrust reverser cascade via an intermediate transmission, for example a rack of thrust movements.

Returning to fig. 3, each row of blades 73 is connected with the gear 31 through the connecting shaft 71, the plurality of gears 31 are meshed with the racks 32 to perform linkage, the gears 31 of the blades 73 in different rows rotate simultaneously through the racks 32, and when the gears 31 or the racks 32 move under the driving of external force, the outflow angle of the airflow of the blades 73 is changed simultaneously, so that the direction of the airflow thrust is controlled.

Fig. 3 shows a zero thrust state of the blade cascade, in which the exit angle of the blade 73 is 90 degrees to the engine axis, i.e. the flight direction 52 is substantially perpendicular to the reverse thrust air flow direction 51, by means of the transmission device, so that when the air flow exits from the reverse thrust blade cascade, the blade cascade generates no thrust on the engine.

Fig. 4 shows a negative thrust (thrust reversal) state of the cascade, in which the exit angle of the blade 73 is less than 90 degrees from the engine axial direction, i.e. the flight direction 52 is at an acute angle to the thrust reversal airflow direction 51, by means of the transmission, so that the airflow is discharged from the thrust reversal cascade, thereby generating a negative thrust on the engine. The outlet angle of the blade 73 is continuously changed, the magnitude of the negative thrust can be correspondingly changed, the blade has wider application conditions compared with a fixed traditional blade cascade, and the speed can be reduced by applying the reverse thrust when the speed of the airplane is lower.

Fig. 5 shows a positive thrust state of the cascade, in which the outlet angle of the vane 73 is greater than 90 degrees from the axial direction of the engine, i.e. the flight direction 52 is at an obtuse angle to the thrust reversal direction 51, so that the airflow is discharged from the thrust reversal cascade, thereby generating positive thrust to the engine. The blade cascade blade outlet angle is continuously changed, the positive thrust can be correspondingly changed, and the blade cascade has the function of adjusting the thrust compared with a fixed blade cascade.

Conventional thrust reversals can only be applied at aircraft speeds above 60 knots, with speeds below 60 knots risking the ingestion of thrust reversals. Through the regulation of the outlet angle of the blades 73, the continuous change from positive thrust to zero thrust to negative thrust (reverse thrust) can be realized, so that the danger of sucking reverse thrust airflow can be effectively reduced, the reverse thrust is not limited to the speed of more than 60 knots, the reverse thrust can be played in a longer time, and the deceleration efficiency of the airplane is improved.

When the airplane is opened by reverse thrust in the air accidentally, the forward thrust of the airplane can be kept through the change of the outlet angle of the blades 73, the airplane stalling caused by the reverse thrust is avoided, the probability of serious accidents is reduced, and the safety of the airplane and the engine is improved.

In the landing process of the airplane, the change from positive thrust to zero thrust to negative thrust can be realized through the change of the outlet angle of the blades 73, the change of the speed of the airplane is smoother, and the maneuverability of the airplane is improved.

Although the preferred embodiments of the present invention have been disclosed, the present invention is not limited thereto, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention, all without departing from the content of the technical solution of the present invention, fall within the scope of protection defined by the claims of the present invention.

Claims

1. The reverse thrust blade cascade comprises a fixed frame and a plurality of rows of blades, and is characterized by further comprising a connecting shaft and a transmission device, wherein each row of blades are respectively installed on the connecting shaft, the connecting shaft is rotatably arranged on the fixed frame, and the transmission device is respectively connected with each connecting shaft and used for receiving power output of a driving device so as to drive each connecting shaft to synchronously rotate.

2. The thrust reverser cascade of claim 1 wherein the transmission comprises a rack and a plurality of gears, the plurality of gears and the plurality of connecting shafts being connected respectively, the rack engaging the plurality of gears, the rack or one of the gears being adapted to receive the power output of the drive.

3. The thrust reverser cascade of claim 1 wherein the transmission comprises a worm and a plurality of worm wheels, the plurality of worm wheels and the plurality of worms being coupled to one another, the worm engaging the plurality of worm wheels, the or one of the worm wheels being adapted to receive the power output of the drive.

4. The thrust reverser cascade of claim 1 wherein the fixed frame comprises an outer frame in which the plurality of rows of vanes are disposed, and a plurality of transverse fixing plates rotatably supported by the outer frame at both ends of the connecting shaft, the transverse fixing plates being orthogonal to the respective rows of vanes and supporting the connecting shaft, the transverse fixing plates passing through the slits of the respective rows of vanes.

5. The thrust reverser cascade of claim 4 wherein the transverse fixing plate and/or the outer frame is provided with a guide member, the blades are provided with guide mating members, and the guide member and the guide mating members are slidably engaged to guide the blades to rotate around the connecting shaft.

6. The reverse thrust cascade of claim 1, wherein the plurality of rows of blades are configured to be rotationally switched between at least three positions including a cascade zero reverse thrust position, a cascade reverse thrust position, and a cascade positive thrust position.

7. Cascade thrust reverser comprising a plurality of thrust reversers surrounding an annulus, characterized in that it further comprises driving means, said thrust reversers being as defined in any one of claims 1 or 4 to 6, said driving means outputting power to said transmission means, respectively.

8. The cascade thrust reverser according to claim 7, wherein the driving devices are multi-position cylinders, each of the thrust reversers corresponds to one of the driving devices, the transmission comprises a rack and a plurality of gears, the plurality of gears and the plurality of connecting shafts are respectively connected, the rack is engaged with the plurality of gears, and the rack is used for receiving the power output of the driving device.

9. The cascade thrust reverser according to claim 7, wherein the driving devices are motors, each of the thrust reversers corresponds to one of the driving devices, the transmission device comprises a worm and a plurality of worm wheels, the worm wheels and the worms are respectively connected, the worm is meshed with the worm wheels, and the worm or one of the worm wheels is used for receiving the power output of the driving device.