CN116291950A

CN116291950A - Ram air turbine emergency energy drive and aircraft

Info

Publication number: CN116291950A
Application number: CN202310099535.8A
Authority: CN
Inventors: 赵文豪; 杨溢炜; 王茜
Original assignee: Commercial Aircraft Corp of China Ltd
Current assignee: Commercial Aircraft Corp of China Ltd
Priority date: 2023-02-10
Filing date: 2023-02-10
Publication date: 2023-06-23

Abstract

The invention relates to a ram air turbine emergency energy drive device, comprising: a first set of turbine blades and a second set of turbine blades coaxially arranged in the axial direction, wherein the second set of turbine blades is rotatable about the axial direction relative to the first set of turbine blades from a first position in which the first set of turbine blades overlap the second set of turbine blades to a second position in which the first set of turbine blades are at a predetermined non-zero angle to the second set of turbine blades and maintained in the second position. Therefore, under the condition that the space in the ram air turbine cabin is not influenced, the number of blades is increased, so that the turbine cranking speed is higher, and the time of accessing the RAT into a power grid is reduced. In addition, the wind energy conversion energy efficiency of the turbine can be improved by increasing the number of the blades, and further the emergency power generation efficiency is improved. The invention also relates to an aircraft comprising a ram air turbine emergency energy drive.

Description

Ram air turbine emergency energy drive and aircraft

Technical Field

The invention belongs to an aircraft emergency energy driving system, relates to a ram air turbine emergency energy driving device, and particularly relates to a rotatable unfolding aircraft emergency energy turbine driving structure. In addition, the invention also relates to an aircraft.

Background

Ram Air Turbine (RAT) emergency power generation device is an emergency Turbine power generation unit used by an aircraft when a double-generator fails. The device is driven by aerodynamic force generated by a flow field when the aircraft flies, and provides hydraulic energy required by emergency landing operation and power required by electricity users for the aircraft.

The ram air turbine emergency power generation device works by utilizing the pneumatic energy of an aircraft, in an emergency working condition, the ram air turbine is released from the aircraft in an emergency mode, the ram air turbine drives turbine blades by utilizing rapid ram air inflow, and the turbine is connected to a generator or a hydraulic drive pump through a gearbox.

The ram air turbine emergency energy driving device of the large civil aircraft is generally arranged in a region with good aerodynamic performance, and the specific arrangement position of the ram air turbine emergency energy driving device needs to balance various factors such as blade size, arrangement space and the like, so that an optimal scheme is finally obtained. Because of space limitations on aircraft, current ram air turbine designs are typically of a double-bladed construction, requiring an increase in blade length or number of blades to increase power generation efficiency, but larger door openings can affect the strength of the aircraft main structure, and therefore RAT blade numbers are typically limited to 2-bladed constructions due to RAT door opening size limitations.

In order to improve the power generation efficiency and reduce the occupation area and maintenance cost of the ram air turbine. In the invention patent with publication number CN108775262A entitled "ram air turbine pitch mechanism", which is filed by Beijing petrochemical institute in 30 months of 2018, a ram air turbine pitch mechanism is provided, which is arranged in a shell of a ram air turbine and is connected with blades through a blade connecting shaft, and comprises a gear rack plate and an expansion joint secondary baffle which are transversely fixed at the front part and the rear part in the shell, wherein an expansion joint baffle is arranged between the gear rack plate and the expansion joint secondary baffle, a gear bar is arranged between the gear rack plate and the expansion joint baffle, and an expansion joint is arranged between the expansion joint baffle and the expansion joint secondary baffle; the gear strip is meshed with a gear fixed at the inner end of the blade connecting shaft. The optimum attack angle can be always kept when the ram air turbine blade works, and the blade can be automatically feathered after the work is finished. However, this structure is still a two-blade configuration, and there is a limit to the improvement of the power generation efficiency.

Accordingly, there is a great need to optimize the construction of ram air turbine emergency energy drives that overcome one or more of the disadvantages of the prior art.

Disclosure of Invention

The invention aims to provide a ram air turbine emergency energy driving device, which enables the turbine to start and rotate faster by increasing the number of blades, can reduce the time for a RAT to access a power grid, greatly improves the efficiency of converting energy by wind energy and emergency power generation efficiency of the turbine, can improve heavy load carrying capacity and reduces low-speed power supply limiting envelope.

According to one aspect of the present invention, a ram air turbine emergency energy drive is presented, which may comprise:

a first set of turbine blades and a second set of turbine blades coaxially arranged in the axial direction, wherein the second set of turbine blades is rotatable about the axial direction relative to the first set of turbine blades from a first position to a second position and maintained in the second position,

wherein in the first position the first set of turbine blades overlaps the second set of turbine blades, and in the second position the first set of turbine blades makes a predetermined non-zero angle with the second set of turbine blades.

Therefore, under the condition that the space in the ram air turbine cabin is not influenced, the number of blades is increased, so that the turbine cranking speed is higher, and the time of accessing the RAT into a power grid is reduced. In addition, the wind energy conversion energy efficiency of the turbine can be improved by increasing the number of the blades, and further the emergency power generation efficiency is improved.

According to the above aspect of the invention, preferably, the first set of turbine blades may be secured to a first mount and the second set of turbine blades may be secured to a second mount, wherein the first mount and the second mount have complementary shaped mating structures such that in the second position the first mount and the second mount are form-fitted together and movement of the second mount relative to the first mount is restricted.

In this way, the first and second mounting members are form-fitted together by means of a form fit, so that in the second position the first set of turbine blades remains stationary relative to the second set of turbine blades, thereby ensuring a stable and safe operation of the ram air turbine emergency energy drive.

According to the above aspect of the present invention, preferably, the first mount may include a first shaft provided with a radial protrusion at an end toward the second mount, and the second mount may include a receiving portion, wherein the receiving portion is configured to guide the radial protrusion in the axial direction, and wherein the receiving portion is provided with a diameter reduced portion at the end toward the first mount.

By this axial arrangement, the first and second sets of turbine blades are not only able to rotate circumferentially relative to each other, but are also able to move in an axial direction relative to each other to adjust the axial distance between the first and second sets of turbine blades, thereby further improving the wind energy conversion energy efficiency.

According to the above aspect of the present invention, preferably, the first mount may include a first flange and a first groove that are disposed at intervals around the circumferential direction, and the second mount may include a second flange and a second groove that are disposed at intervals around the circumferential direction, wherein in the second position, the first flange is fitted into the second groove, and the second flange is fitted into the first groove.

By this arrangement it can be ensured that in the second position the first and second mounting parts are more reliably secured together by means of a form fit, ensuring reliability and stability of the coupling, in particular in the circumferential and axial direction.

According to the above aspect of the invention, preferably, the first flange may be provided with a first slide rail and the first groove may be provided with a second slide rail, and the second flange is provided with a first slider, wherein in the first position the first slider is fitted into the first slide rail and in the second position the first slider is fitted into the second slide rail.

In this way, the first and second mounting elements are allowed to perform a relative movement, in particular a circumferential movement, with respect to each other according to a predetermined path, and the reliability and stability of the coupling, in particular in the radial direction, are ensured.

According to the above aspect of the invention, preferably, the first slide rail may form a through opening in the first circumferential direction toward an end of the first flange, and be closed at an opposite end to restrict rotation of the second mount relative to the first mount only in the first circumferential direction.

In this way, the first rail is made to open in only one direction to allow the second mount to rotate in only one direction relative to the first mount and only a circumferential distance through one flange or groove, since the closed end prevents continued rotation of the second mount relative to the first mount, thereby avoiding as much as possible the second set of turbine blades from idling relative to the first set of turbine blades.

According to the above aspect of the present invention, preferably, a biasing member may be provided between the first mount and the second mount, the biasing member biasing the second mount toward the first mount. The biasing member may force the second mount to move closer to the first mount with ram air.

In accordance with the above aspect of the invention, alternatively and additionally preferably, a biasing member may be provided between the first mount and the second mount, the biasing member biasing the second mount away from the first mount. The biasing member may assist in returning the second set of mounts to the first, stowed position relative to the first set of mounts when no ram air is acting on the second set of turbine blades, such as when the ram air turbine emergency energy drive is not in operation (e.g., after the aircraft is dropped), thereby facilitating a RAT stow operation by maintenance personnel.

According to the above aspect of the present invention, preferably, each of the first and second sets of turbine blades may include two turbine blades arranged in a straight line. In this way, compared with existing ram air turbine emergency energy drives, the occupied and open space requirements are not increased, facilitating retrofitting on existing aircraft.

According to the above aspect of the invention, preferably, in the second position, the first set of turbine blades and the second set of turbine blades may be in the same rotation plane, thereby further improving the wind energy utilization of the ram air turbine emergency energy drive.

In accordance with the above aspect of the invention, to further enhance wind energy utilization, preferably, in the second position, the first set of turbine blades may be at an angle of 90 degrees to the second set of turbine blades.

According to a further aspect of the invention, an aircraft is proposed, which may comprise a ram air turbine emergency energy drive according to any of the above aspects.

The ram air turbine emergency energy drive of the present invention includes, but is not limited to, the following listed advantages:

1) The device can greatly improve the efficiency of converting energy by wind energy by the turbine and the emergency power generation efficiency by increasing the number of the blades;

2) According to the device, the number of the blades is increased, so that the turbine cranking speed is higher, and the time of the RAT accessing to a power grid can be reduced;

3) The device has stronger carrying capacity by increasing the number of the blades, and can greatly improve the carrying capacity of heavy load of the turbine;

4) The device of the invention has higher wind energy extraction efficiency and smaller emergency power supply low-speed limit by increasing the number of the blades.

The ram air turbine emergency energy drive according to the invention thus meets the requirements of use, overcomes the disadvantages of the prior art and achieves the intended aim.

Drawings

For a further clear description of the ram air turbine emergency energy drive according to the invention, the invention will be described in detail below with reference to the drawings and to the specific embodiments, in which:

FIG. 1 schematically illustrates wind energy utilization coefficient versus tip speed ratio for a ram air turbine emergency energy drive;

FIG. 2 is a schematic view of a ram air turbine emergency energy drive in a first position according to a non-limiting embodiment of the invention;

FIG. 3 is a schematic view of a ram air turbine emergency energy drive in a second position according to a non-limiting embodiment of the invention;

FIG. 4 is a schematic perspective view of a portion of a ram air turbine emergency energy drive in accordance with the invention;

FIG. 5 is a schematic top view of a portion of a ram air turbine emergency energy drive according to the invention;

FIG. 6 is a schematic perspective view of another portion of the ram air turbine emergency energy drive according to the invention; and

fig. 7 is a schematic cross-sectional view of a portion of a ram air turbine emergency energy drive according to the invention.

The figures are merely schematic and are not drawn to scale.

List of reference numerals in the figures and examples:

a 100-ram air turbine emergency energy drive comprising:

10-a first set of turbine blades;

20-a second set of turbine blades;

a first mount, comprising:

30A-a first axis;

31-a first flange;

31A-a first slide rail;

32-a first groove;

32A-a second slide rail;

40a second mount comprising:

40A-a receiving portion;

41-a second flange;

41A-a first slider;

42-a second groove;

a 50-bias member;

a-axial direction;

b-first circumferential direction.

Detailed Description

It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It should be further understood that the specific devices illustrated in the accompanying drawings and described in the specification are simply exemplary embodiments of the inventive concepts disclosed and defined herein. Thus, unless explicitly stated otherwise, the particular orientations, directions, or other physical characteristics to which the various embodiments disclosed relate should not be considered limiting.

Ram Air Turbine (RAT) emergency power generation devices are important equipment for emergency power systems and hydraulic systems of aircraft. RAT systems are the last emergency means when the aircraft main engine is stopped and the auxiliary power system (APU) fails. The RAT is normally housed inside the fuselage of the aircraft, inside the wings or in the doors of the landing gear. When the aircraft is in operation, the ram air turbine is ejected, and the front end blade is blown by the incoming airflow during the flying process and drives the engine or the small hydraulic machine to operate, so that emergency power supply or hydraulic supply is provided for the aircraft.

Because of space limitations on aircraft, current aircraft ram air turbine designs are typically double bladed structures, and if the blade length or number of blades is to be increased to increase power generation efficiency, the larger door opening can affect the strength of the aircraft main structure, and therefore RAT blade number is typically limited to 2 blades due to RAT door opening size limitations.

FIG. 1 schematically illustrates wind energy utilization coefficient versus tip speed ratio for a ram air turbine emergency energy drive.

The larger the blade size of the ram air turbine, the greater the tip speed ratio. The tip speed ratio is the ratio of the linear velocity of the tip of the wind turbine blade to the undisturbed air flow velocity at the upstream of the turbine, and is represented by lambda, and the calculation formula is as follows:

wherein ω -turbine rotational angular velocity in rad/s;

r is turbine radius, and the unit is m;

v _∞ -the undisturbed gas flow velocity upstream of the turbine in m/s.

Substituting ω=2ρn into the above formula, where n is turbine speed in rpm/s, yields:

the wind energy utilization coefficient is the ratio of the output power of the turbine to the wind power of the free flow velocity corresponding to the swept area, C _p The expression, therefore, turbine output power P is calculated as:

wherein P is turbine output power, and the unit is W;

ρ -air density in kg/m ³ ；

A _d Turbine swept area in m ² 。

Ram air turbine speeds are typically 6800rpm/min, with aircraft airspeeds in the air greater than 130kn (knots) and less than 0.8ma (mach), if the ram air turbine radius is 0.6m. If the influence of the shape of the blade, the pitch change and the like is not considered, the blade tip speed ratio of the low-speed characteristic is estimated to be 5.57, and at the moment, the wind energy utilization coefficient is 0.2 for 2 blades and 0.38 for 4 blades. The wind energy utilization rate and the turbine output power are improved by about 2 times, and the wind energy utilization rate and the turbine output power can be greatly improved. The adoption of the multi-blade design improves the low-speed heavy load starting capability (such as an on-load electric hydraulic pump).

If the 4-blade design and the 2-blade design have the same turbine output power, the length of the 4-blade design can be 0.707 of the 2-blade length, so that the space occupied by the turbine blade of the 4-blade design can be smaller, the size of the opening of the RAT cabin door is smaller, and the influence on the machine body structure is minimum.

The invention therefore proposes a ram air turbine emergency energy drive for an aircraft emergency energy, by providing two sets of turbine blades, for example two sets of turbine blades coaxially arranged in the axial direction (for example arranged one behind the other) in an initial state, which enable an increase in the number of blades without affecting the space in the ram air turbine compartment. In this way, the turbine cranking speed is faster, and the time for the RAT to access the power grid can be reduced. In addition, through increasing blade quantity, also can promote the efficiency that the turbine utilized wind energy conversion energy, and then promote emergent generating efficiency.

As a non-limiting example, the device may have multiple sets of turbine blades, such as two sets of turbine blades. For example, in an initial state or position, the two sets of turbine blades are arranged one after the other in an axial direction, e.g. coaxially. After ejection out of the nacelle, the two sets of turbines can be rotated relative to each other under wind force, thereby being connected as a four-bladed turbine. The multi-blade turbine can improve energy conversion efficiency and power generation efficiency by utilizing wind energy and reduce the time of accessing the RAT into a power grid.

Fig. 2 is a schematic view of the ram air turbine emergency energy drive 100 according to a non-limiting embodiment of the invention in a first position, and fig. 3 is a schematic view of the ram air turbine emergency energy drive 100 according to a non-limiting embodiment of the invention in a second position.

According to the invention, the first position (or state) in which the ram air turbine is not operating may be a position in which the ram air turbine is stowed inside the aircraft. The second position (or state) may be a position in which the ram air turbine has been ejected outside the aircraft and has been rotated into position, in which the ram air turbine is ready to start working or is in operation.

As shown and according to a non-limiting embodiment, the ram air turbine emergency energy drive 100 may comprise a first set of turbine blades 10 and a second set of turbine blades 20 coaxially arranged in the axial direction a. For example, the second set of turbine blades 20 may be arranged in front of the first set of turbine blades 10 facing the ram air flow. In the example shown in the drawings, the first set of turbine blades 10 and the second set of turbine blades 20 may each comprise two turbine blades arranged in a straight line. The size and shape of each turbine blade may be the same and the turbine blade has a predetermined angle of deflection on its surface such that it rotates in a predetermined direction under the influence of ram air.

As shown, in the first position, the first set of turbine blades 10 is stacked with the second set of turbine blades 20, e.g., in tandem alignment, to minimize the space required for stowing and releasing.

In addition, although not shown in the drawings, the ram air turbine emergency energy drive 100 may also be provided with a locking mechanism for locking the first set of turbine blades 10 and the second set of turbine blades 20 in a first position to lock them in a position on top of each other without interfering with the rest of the components, in particular during release from the nacelle.

According to the invention, the second set of turbine blades 20 is rotatable relative to the first set of turbine blades 10 about the axial direction a from a first position (the position shown in fig. 2) to a second position (the position shown in fig. 3) and is maintained in the second position, for example after unlocking of the locking means. In the second position, the first set of turbine blades 10 may be at a predetermined non-zero angle with the second set of turbine blades 20, such as the substantially 90 degree angle shown in FIG. 3.

The first set of turbine blades 10 may be secured to the first mount 30 and the second set of turbine blades 20 may be secured to the second mount 40. For example, the first and second mounting

members

30, 40 are coaxially mounted and each may have a hub-like structure and the interior may be generally hollow. Two blades of the first set of turbine blades 10 may extend from the side of the first mount 30 such that the two blades are arranged in a straight line. Likewise, blades (e.g., two blades) of the second set of turbine blades 20 may extend from the side of the second mount 40 such that the two blades are arranged in a straight line.

According to the present invention, for simplicity, the combination of the first set of turbine blades 10 and the first mount 30 may be referred to as a first set of turbines, and the combination of the second set of turbine blades 20 and the second mount 40 may be referred to as a second set of turbines.

It should be appreciated that while the present invention has been described with reference to an embodiment in which each set of turbine blades includes two blades, those skilled in the art may contemplate the remaining types of blade numbers and arrangements without departing from the scope of the present invention.

According to a non-limiting embodiment of the invention, the first mounting member 30 and the second mounting member 40 may have complementary shaped mating structures such that in the second position the first mounting member 30 and the second mounting member 40 are form-fitted together and, at this time, such mating structures limit relative movement between the first mounting member 30 and the second mounting member 40, such as any circumferential movement therebetween, and may limit axial movement therebetween, such as with the aid of ram air or with the aid of the remaining components.

Fig. 4 is a schematic perspective view of a portion of a ram air turbine emergency energy drive 100 according to the invention; FIG. 5 is a schematic top view of a portion of a ram air turbine emergency energy drive 100 according to the invention; and figure 6 is a schematic perspective view of another part of a ram air turbine emergency energy drive 100 according to the invention.

As shown, as an example of the complementary-shaped mating structure, the first mount 30 may include first flanges 31 and first grooves 32 (see fig. 4) spaced around the circumferential direction, and the second mount 40 may include second flanges 41 and second grooves 42 (see fig. 6) spaced around the circumferential direction. The flanges and grooves may be equally spaced apart from one another such that each flange and groove corresponds to approximately one quarter of a circumference.

Thus, in the second position, the first flange 31 may fit into the second groove 42 and the second flange 41 may fit into the first groove 32, e.g., such that the flange and groove snap fit together exactly (as shown in fig. 3). With their engagement, the axial distance between the first set of turbine blades 10 and the second set of turbine blades 20 also changes so that they may be in the same plane of rotation to increase the efficiency of the turbine to convert energy from wind energy.

With continued reference to fig. 4-6, the first flange 31 is provided with a first slide rail 31A in the form of a guide slot, and the first groove 32 is provided with a second slide rail 32A in the form of a guide slot (see shown in fig. 4 and 5). Accordingly, the second flange 41 may be provided with a first slider 41A, the first slider 41A may protrude from an axial end of the second flange 41, for example, and its circumferential profile follows the shape of the second flange 41.

Thus, in the first position, the first slider 41A may be fitted into the first slide rail 31A (as shown in fig. 2), and in the second position, the first slider 41A may be fitted into the second slide rail 32A (as shown in fig. 3).

As a non-limiting example, after the RAT release, the second set of turbines may be first unlocked for rotation, at which point the wind speed forces act rearwardly against the turbines. When the second flange 41 of the second set of turbines starts to enter the first groove 32 of the first set of turbines, the second set of turbines starts to move backwards in the first groove 32 under the influence of the wind (and possibly the biasing member). Meanwhile, the second flange 41 of the second turbine group contacts with the side wall of the first flange 31 of the first turbine group in the rotating process, so that the second flange 41 and the first slider 41A of the second turbine group are correspondingly and completely overlapped with the first groove 32 and the second slide rail 32A of the first turbine group, and meanwhile, the first flange 31 of the first turbine group is overlapped with the second groove 42 of the second turbine group, and finally, the two turbine groups are positioned in the same horizontal rotating plane.

Thus, upon release of the over-the-air RAT, the second set of turbine blades 20 begins to rotate, and under the influence of wind (and possibly the biasing member), the second flange 41 of the second set of turbine blades may rotate into the first recess 32 of the first set of turbines, the two sets of blades forming a four-bladed turbine blade, as shown in fig. 3, which increases the number of rotating blades, improving the efficiency of harnessing the wind energy.

It should be understood that while the present invention describes a form-fitting manner between the first mounting member 30 and the second mounting member 40 by way of flanges and grooves, other types of structures capable of achieving a form-fitting connection therebetween are within the scope of the present invention. For example, each mounting member is provided with a sloped ramp to wedge together structures or the like.

As best shown in fig. 4, the first slide rail 31A forms a through opening in the first circumferential direction B toward the end of the first flange 31 and is closed at the opposite end to restrict rotation of the second mount 40 relative to the first mount 30 only in the first circumferential direction B and not in the opposite direction. In addition, by this arrangement, the range of relative circumferential movement between the second mount 40 when rotated relative to the first mount 30 does not exceed the circumferential length of the first flange 31 or the second flange 41, as the closed end blocks continued rotation of the second mount 40 relative to the first mount 30 in the first circumferential direction B. In this way, this arrangement allows only the second mount 40 to be rotated relative to the first mount 30 from the first position to the second position and remain in that second position without further rotation unless adjusted manually after inapplicability to return to the first position.

Fig. 7 is a schematic cross-sectional view of a portion of a ram air turbine emergency energy drive 100 according to the invention.

In fig. 7, a constraining mechanism of the axial movement of the second mount 40 relative to the first mount 30 is shown. As shown and according to a non-limiting embodiment, the first mount 30 may include a first shaft 30A, and the first shaft 30A may be integral with the first mount 30 and may serve as a rotating shaft that transmits rotation of the blades to a gearbox or generator. The first shaft 30A is provided with a radial protrusion at an end toward the second mount 40 (i.e., the right end in fig. 7).

The second mount 40 may include a receiving portion 40A, and the receiving portion 40A may be of a generally cylindrical configuration and extend from an end face of the second mount 40 toward the first mount 30. The receptacle 40A is configured to guide a radial projection, such as a piston guide, in the axial direction a to accommodate axial movement of the second mount 40 relative to the first mount 30. The accommodation 40A is provided with a reduced diameter portion at an end facing the first mount 30, which may cooperate with the radial projection to prevent the first shaft 30A from coming out of the accommodation 40A.

Thus, in a first position, the radial projection may abut against the reduced diameter portion to limit movement of the second mount 40 away from the first mount 30 in the axial direction a, while in a second position, the radial projection may move from the reduced diameter portion to the end face of the second mount 40 and abut against or be in a gap with the end face to allow movement of the second mount 40 toward the first mount 30 in the axial direction a, thereby moving axially from the first position to the second position and remaining in the second position.

Referring back to fig. 4, as shown, the ram air turbine emergency energy drive 100 according to the present invention may include a biasing member 50, and the biasing member 50 may be disposed about the first shaft 30A between the first mount 30 and the second mount 40. The biasing member 50 may be used to bias the second mount 40 toward the first mount 30 so as to cooperate the second mount 40 with the first mount 30 together with the ram air during deployment of the second set of turbine blades toward the second position, e.g., such that the first flange 31 mates into the second groove 42 and the second flange 41 mates into the first groove 32.

Alternatively, the biasing member 50 may be used to bias the second mount 40 away from the first mount 30 to move the second set of mounts 40 away from the first set of mounts 30 when the ram air turbine emergency energy drive 100 is not in operation, such as after an aircraft is dropped, to facilitate returning it to the first position to stow the RAT. It will be appreciated that the biasing force at this time should be relatively small so that when deployed to the second position, the ram air force is able to move the second set of mounts 40 in the axial direction a toward the first mount 30 against the biasing force of the biasing member 50.

In the embodiment shown in the drawings, the biasing member 50 is shaped in the form of a linear spring, but in other embodiments, one skilled in the art may provide other types of biasing members, such as various elastomers (e.g., elastomeric composites, etc.).

The terms "front" and "rear" as used herein to indicate orientation or orientation, and the terms "first", "second", etc. used to indicate order, are merely for better understanding of the inventive concept shown in the form of preferred embodiments by those of ordinary skill in the art, and are not intended to limit the invention. Unless otherwise indicated, all orders, orientations, or orientations are used solely for the purpose of distinguishing one element/component/structure from another element/component/structure, and do not denote any particular order, order of operation, direction, or orientation unless otherwise indicated. For example, in alternative embodiments, the "first set of turbine blades" may be the "second set of turbine blades" and the "first mount" may alternatively refer to the "second mount".

In summary, the ram air turbine emergency energy drive 100 according to embodiments of the present invention overcomes the shortcomings of the prior art and achieves the intended aim.

While the ram air turbine emergency energy drive of the present invention has been described in connection with a preferred embodiment, those of ordinary skill in the art will recognize that the foregoing examples are for illustrative purposes only and are not intended to be limiting. Accordingly, the present invention may be variously modified and changed within the spirit of the claims, and all such modifications and changes are intended to fall within the scope of the claims of the present invention.

Claims

1. A ram air turbine emergency energy drive (100), the ram air turbine emergency energy drive comprising:

a first group of turbine blades (10) and a second group of turbine blades (20) coaxially arranged in an axial direction (A), wherein the second group of turbine blades (20) is rotatable relative to the first group of turbine blades (10) about the axial direction (A) from a first position to a second position and maintained in the second position,

wherein in the first position the first set of turbine blades (10) overlaps the second set of turbine blades (20), and in the second position the first set of turbine blades (10) makes a predetermined non-zero angle with the second set of turbine blades (20).

2. The ram air turbine emergency energy drive (100) of claim 1, wherein the first set of turbine blades (10) is secured to a first mount (30) and the second set of turbine blades (20) is secured to a second mount (40), wherein the first mount (30) and the second mount (40) have complementary mating structures such that in the second position the first mount (30) and the second mount (40) are form-fit together and limit movement of the second mount (40) relative to the first mount (30).

3. The ram air turbine emergency energy drive (100) of claim 2, wherein the first mount (30) comprises a first shaft (30A) provided with a radial protrusion at an end facing the second mount (40), the second mount (40) comprising a receptacle (40A), wherein the receptacle is configured to guide the radial protrusion in the axial direction (a), and wherein the receptacle is provided with a reduced diameter portion at an end facing the first mount (30).

4. The ram air turbine emergency energy drive (100) of claim 2, wherein the first mount (30) comprises a first flange (31) and a first groove (32) spaced around a circumferential direction, and the second mount (40) comprises a second flange (41) and a second groove (42) spaced around the circumferential direction, wherein in the second position the first flange (31) fits into the second groove (42) and the second flange (41) fits into the first groove (32).

5. The ram air turbine emergency energy drive (100) of claim 4, wherein the first flange (31) is provided with a first slide rail (31A) and the first groove (32) is provided with a second slide rail (32A) and the second flange (41) is provided with a first slider (41A), wherein in the first position the first slider (41A) fits into the first slide rail (31A) and in the second position the first slider (41A) fits into the second slide rail (32A).

6. The ram air turbine emergency energy drive (100) of claim 5, wherein the first slide rail (31A) forms a through opening in a first circumferential direction (B) towards an end of the first flange (31) and is closed at an opposite end to constrain the second mount (40) from rotating relative to the first mount (30) only in the first circumferential direction (B).

7. Ram air turbine emergency energy drive (100) according to claim 2, characterized in that a biasing member (50) is provided between the first mount (30) and the second mount (40), the biasing member biasing the second mount (40) towards the first mount (30).

8. Ram air turbine emergency energy drive (100) according to any of claims 1-7, wherein the first set of turbine blades (10) and the second set of turbine blades (20) each comprise two turbine blades arranged in a line.

9. Ram air turbine emergency energy drive (100) according to any of claims 1-7, wherein in the second position the first set of turbine blades (10) is in the same plane of rotation as the second set of turbine blades (20).

10. An aircraft comprising a ram air turbine emergency energy drive (100) according to any one of claims 1-9.