Tilting system for an aircraft propeller

Abstract

Tilting system for an aircraft propeller (A), wherein the tilting system comprises: a housing (100) with an interior and with an opening section (O) at an end section of the housing (100); a propeller (300) which is provided in front of the opening section (O) of the housing (100) and is configured to be tilted selectively with respect to the housing (100); a connecting element assembly (500), wherein a first end section of the connecting element assembly (500) is coupled to the housing (100) and a second end section of the connecting element assembly (500) is coupled to the propeller (300) and is configured to tilt the propeller (300) up or down when the connecting element assembly (500) is extended from or retracted into the housing (100); and an actuator (700) that is coupled and formed with the connecting element arrangement (500),to provide energy for extending or retracting the connecting element assembly (500), wherein the connecting element assembly (500) comprises an upper connecting element (540) and a lower connecting element (520), the length of the lower connecting element (520) being greater than the length of the upper connecting element (540), and wherein the lower connecting element (520) comprising at least a portion connected to a hinge (522) which is connected to the actuator (700), wherein a forward movement of the upper connecting element (540) is limited by a stop element (542) which is arranged in the housing (100) at a point of maximum forward movement, and wherein the actuator (700) is coupled to the lower connecting element (520), and wherein the lower connecting element (520) is provided with a cylinder,and wherein at least one part of the lower connecting element (520) is moved rearward into the cylinder or forward to an outside of the cylinder.

Description

BACKGROUND OF THE INVENTION Field of invention The present invention relates to a tilting system for a propeller of an aircraft. Description of the state of the art An aircraft performs both lift and cruise maneuvers during flight. It is therefore common practice to provide a lift propeller and a cruise propeller, one for lift maneuvers and one for cruise maneuvers. However, the lift propeller is not used in cruise flight, and the presence of the lift propeller is rather a disadvantage in terms of aerodynamic performance. Therefore, a comprehensive development of tilting propellers took place, so that a single propeller can be tilted up or down depending on the environment in which it is used, in order to fulfill both purposes. However, a conventional tilting propeller has a problem in that, since it can only be tilted in a fixed location, the wing or boom to which the propeller is attached lies directly below the propeller when tilting, with the underlying wing or boom reducing thrust during tilting. Therefore, there is a need for a technology capable of realizing a propeller that can not only perform a simple tilting motion using a single actuator, but can also glide forward when tilted, thus preventing a reduction in thrust during a lift motion. From CN 1 08 910 030 A, a tilting system for an aircraft propeller is known, wherein the tilting system comprises: a housing with an interior and with an opening section at an end section of the housing; a propeller provided in front of the opening section of the housing and configured to be tilted selectively with respect to the housing; a connecting element assembly, wherein a first end section of the connecting element assembly is coupled to the housing and a second end section of the connecting element assembly is coupled to the propeller and configured to tilt the propeller up or down when the connecting element assembly is extended from or retracted into the housing; and an actuator coupled to the connecting element assembly and configured to provide energy for extending or retracting the connecting element assembly. US Patent 2020 / 0148347A1 discloses an aircraft with an airframe and several propulsion assemblies connected to the airframe, wherein each propulsion assembly comprises an electric motor, a propeller connected to the electric motor, and a tilting mechanism that connects the propulsion assembly to the airframe and converts the propulsion assembly between a forward configuration and a hover configuration; wherein the several propulsion assemblies are convertible between a forward arrangement and a hover arrangement, with each of the several propulsion assemblies being in the forward configuration in the forward arrangement and each of the several propulsion assemblies being in the hover configuration in the hover arrangement, and wherein the distance between at least two of the propellers of the several propulsion assemblies changes between the forward arrangement and the hover arrangement. The information disclosed in this section concerning the background of the invention is intended solely to provide a better understanding of the general background of the invention and should not be construed as an acknowledgment or any kind of indication that this information constitutes the prior art already known to the person skilled in the art. QUICK OVERVIEW The object of the present invention is to provide a tilting system for an aircraft propeller, wherein the propeller can not only perform a tilting operation about a single axis, but can also perform forward / backward movements during the tilting, while suppressing a reduction in lift thrust by a wing or boom and maintaining stiffness by using a single actuator as in a conventional system. The problem is solved by a tilting system for an aircraft propeller with the features of claim 1. Advantageous further developments are found in the dependent claims. A tilting system for an aircraft propeller according to various aspects of the present invention comprises: a housing with an interior and with an opening section at an end section of the housing; a propeller provided in front of the opening section of the housing and configured to be selectively tilted with respect to the housing; a connecting element assembly provided in the interior of the housing, the first end section of which is connected to the housing and the second end section of which is connected to the propeller, and configured to tilt the propeller up or down when the connecting element assembly is extended from or retracted into the housing; and an actuator coupled to the connecting element assembly and configured to provide energy for extending or retracting the connecting element assembly.The connecting element arrangement comprises an upper connecting element and a lower connecting element, wherein the length of the lower connecting element is greater than the length of the upper connecting element, and wherein the lower connecting element includes at least a portion connected to a hinge that is connected to the actuator. Forward movement of the upper connecting element is limited by a stop element located in the housing at a point of maximum forward movement, and the actuator is coupled to the lower connecting element. The lower connecting element is provided with a cylinder, and the at least portion of the lower connecting element moves either rearward into the cylinder or forward toward an outer surface of the cylinder. The housing can be a boom or a wing of the aircraft. The propeller can put the aircraft into a lifting motion when the propeller is tilted upwards, and can put the aircraft into a cruising motion when the propeller is tilted downwards. The propeller can close the opening section of the housing when it is tilted downwards. The propeller can open the opening section of the housing when it is tilted upwards, with the propeller positioned perpendicular to the direction in which the housing extends. The connecting element assembly may be contained within the housing when the propeller is tilted downwards, and may be partially exposed to the outside through the opening section when the propeller is tilted upwards. The actuator can move the upper connecting element and the lower connecting element forwards or backwards; the upper connecting element and the lower connecting element can be moved forwards together when the propeller is tilted; the lower connecting element can continue to move forwards after the upper connecting element has been moved fully forwards; the majority of parts of the lower connecting element can be folded relative to the connecting element to raise the propeller for tilting. The actuator can move the upper connecting element and the lower connecting element forwards or backwards, the propeller can be tilted downwards, the lower connecting element can be moved backwards, the majority of the folded sections can be arranged linearly when the upper connecting element and the lower connecting element are moved backwards when the propeller is tilted downwards. The propeller can close the opening section of the housing when the propeller is tilted downwards, while the propeller can be rotated upwards as it moves forwards away from the opening section of the housing when the propeller is tilted upwards. A tilting system for an aircraft propeller according to various exemplary embodiments of the present invention is advantageous in that the propeller can not only perform a tilting operation about a single axis, but can also perform forward / backward movements during the tilting, suppressing a reduction in lift thrust by a wing or boom, and maintaining stiffness by using a single actuator as in a conventional system. The methods and devices of the present invention have further features and advantages which are evident from the accompanying drawings incorporated herein and the following detailed description, or which are explained in more detail therein, which together serve to illustrate certain principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a tilting system for an aircraft propeller according to various exemplary embodiments of the present invention; Fig. 2, Fig. 3 and Fig. 4 are views that exemplarily show a process of tilting a propeller by the tilting system for an aircraft propeller according to the exemplary embodiment of the present invention; and Fig. 5 and Fig. 6 are views that exemplarily illustrate an operation of the tilting system for an aircraft propeller according to the exemplary embodiment of the present invention. It should be assumed that the accompanying drawings are not necessarily to scale, showing a somewhat simplified representation of various features that illustrate the basic principles of the present invention. The specific design features of the present invention, as disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes, are partly determined by the intended application and operating environment. In the figures, the reference numerals refer to the same or equivalent parts of the present invention in the different figures of the drawing. DETAILED DESCRIPTION Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) is / are described in connection with exemplary embodiments of the present invention, it should be understood that the present description is not intended to limit the invention(s) to these exemplary embodiments. On the other hand, the invention(s) is / are intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the scope and spirit of the invention as defined by the accompanying claims. It is understood that the accompanying drawings are not necessarily to scale, showing a somewhat simplified representation of various features that illustrate the basic principles of the present invention. The specific design features of the present invention, as disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes, are partly determined by the intended application and operating environment. In the figures, the reference numerals refer to the same or equivalent parts of the present invention in the different figures of the drawing. Fig. 1 is a perspective view of a tilting system for an aircraft propeller according to various exemplary embodiments of the present invention. Figs. 2, 3, and 4 are views that exemplify the process of tilting a propeller by the tilting system for an aircraft propeller according to an exemplary embodiment of the present invention. Figs. 5 and 6 are views that exemplify the operation of the tilting system for an aircraft propeller according to an exemplary embodiment of the present invention. Fig. 1 is a perspective view of a tilting system for an aircraft propeller according to various exemplary embodiments of the present invention, wherein the tilting system for an aircraft propeller according to various exemplary embodiments of the present invention comprises: a housing 100 with an interior and an opening section at one end section thereof; a propeller 300 provided in the opening section O of the housing 100 and configured to be tilted relative to the housing 100; a connecting element arrangement 500 provided in the interior of the housing 100, one end section of which is connected to the housing 100 and an opposite end section to the propeller 300, and configured to tilt the propeller 300 up or down when the connecting element arrangement 500 is extended or retracted;and an actuator 700 configured to provide energy for extending or retracting the connecting element assembly 500.; According to various exemplary embodiments of the present invention, the thrust loss through a wing or boom located on the underside can be minimized by not only rotating the propeller 300, but also moving it further forward when the propeller 300 is tilted downwards and tilted upwards. To achieve this, the boom or wing in which the propeller 300 is provided is defined as the housing 100. The interior is formed within the housing 100, with the opening section O being located at one end section of the housing 100. The propeller 300 is provided within the opening section O of the housing 100, and the propeller can be tilted relative to the housing 100. In detail, the tilting action of the propeller 300 is implemented by the connecting element assembly 500. The connecting element assembly 500 is provided inside the housing 100, with one end section of the connecting element assembly 500 being connected to the housing 100 and with an opposite end section of the connecting element assembly 500 being connected to the propeller 300, wherein the connecting element assembly 500 tilts the propeller 300 up or down when the connecting element assembly 500 is extended or retracted. The actuator 700 supplies energy to extend or retract the connecting element assembly 500. This means that the housing 100 can be the boom or the wing of the aircraft. The propeller 300 can propel the aircraft A into a lift-generating motion when the propeller is tilted upwards, and can propel the aircraft A into a cruise-like motion when the propeller is tilted downwards. Accordingly, the propeller 300 is tilted upwards to point upwards, as shown in Fig. 4, when it is necessary to propel the aircraft A into a lift-generating motion, and is tilted downwards to point forwards, as shown in Fig. 2, when it is necessary to propel the aircraft A into a cruise-like motion. The propeller 300 can close the opening section O of the housing 100 when it is tilted upwards. Accordingly, the thrust loss for cruise flight can be reduced, and the aerodynamic performance of the aircraft A can be improved by closing the interior of the housing 100 when the aircraft A is in cruise flight, as in the state of Fig. 6. The propeller 300 can open the opening section O of the housing 100 when tilted and can be arranged perpendicular to the direction in which the housing 100 extends. Accordingly, the propeller 300 can be oriented upwards, as shown in Figs. 4 and 6, allowing the aircraft A to take off or land vertically. In this case, opening the opening section O of the housing 100 is unavoidable, but even if this occurs, it does not pose a significant problem since forward thrust is not required. The connecting element arrangement 500 is located inside the housing 100 when the propeller 300 is tilted downwards, and can be partially exposed to the outside through the opening section O when the propeller 300 is tilted upwards. In detail, the connecting element arrangement 500 can comprise an upper connecting element 540 and a lower connecting element 520, and can be configured such that the length of the lower connecting element 520 is greater than the length of the upper connecting element 540, wherein the lower connecting element 520 can comprise a plurality of parts connected with respect to a hinge 522. In this process, the actuator 700 can move the upper connecting element 540 and the lower connecting element 520 forwards or backwards; the upper connecting element 540 and the lower connecting element 520 can be moved forwards together when the propeller 300 is tilted; the lower connecting element 520 can continue to be moved forwards after the upper connecting element 540 has been moved fully forwards; the majority of parts of the lower connecting element 520 can be folded relative to the connecting element 522 to lift the propeller 300, thus tilting the propeller 300. Furthermore, the actuator 700 can move the upper connecting element 540 and the lower connecting element 520 forwards or backwards, the propeller 300 can be tilted downwards, the lower connecting element 520 can be moved backwards, and the majority of the folded sections can be arranged linearly when the upper connecting element 540 and the lower connecting element 520 are moved backwards when the propeller 300 is tilted downwards. Specifically, the forward movement of the upper connecting element 540 can be limited by a stop element 542 of the housing 100 at a point of maximum forward movement, with the actuator 700 being connected to the lower connecting element 520. Furthermore, the lower connecting element 520 can be provided with a cylinder, wherein the majority of parts of the lower connecting element 520 can be moved rearward into the cylinder or forwardward to the outside of the cylinder. The propeller 300 can close the opening section O of the housing 100 when it is tilted downwards, and the propeller can be rotated upwards while being moved forwards by the opening section O of the housing 100 when the propeller is tilted upwards. Fig. 2 is a view illustrating by way of example that the propeller 300 is tilted and in a cruise flight state, Fig. 4 is a view illustrating by way of example that the propeller 300 is tilted and in a lift state, and Fig. 3 is a view illustrating by way of example an intermediate process. Accordingly, the propeller 300 is operated in the sequence of Fig. 2, Fig. 3, and Fig. 4 when it is tilted, and the propeller is changed in the sequence of Fig. 4, Fig. 3, and Fig. 2 when it is tilted downwards. Specifically, the connecting element arrangement 500 comprises two connecting elements. One of the two connecting elements is an upper connecting element 540, which is arranged on the top side, while the other of the two connecting elements is a lower connecting element 520, which is arranged on the bottom side. The length of the lower connecting element 520 is chosen to be slightly longer, since a tilting operation requires a 90-degree upward tilt. In an exemplary embodiment of the present invention, a front end section of the lower connecting element 520 is pivotably connected to the propeller 300 via a hinge 524, wherein a front end section of the upper connecting element 540 is pivotably connected to the propeller 300 via a hinge 544, and wherein a rear end section of the upper connecting element 540 is slidably connected to the housing 100. In an exemplary embodiment of the present invention, the plurality of parts can comprise at least two connecting elements which are connected to the actuator 700 and the propeller via the hinge 522, wherein one of the at least two connecting elements is a connecting element 526 which is connected to the propeller 300 via the hinge 524, and a connecting element 528 which is pivotably connected to the connecting element 526 via the hinge 522 and is slidably engaged with the actuator 700. Furthermore, the lower connecting element 520, for the tilting process, comprises a plurality of parts which are subdivided in relation to the hinge 522. Initially, in the state shown in Fig. 2, the cylindrical actuator 700 is actuated. The actuator 700 is of a type that can be operated electrically or hydraulically and moves the lower connecting element 520 inside it forwards and backwards. The lower connecting element 520 is moved linearly when it is moved forwards by the actuator, thereby also moving the upper connecting element 540 forwards. Furthermore, the upper connecting element 540 is stopped by a stop element 542 of the housing 100 at its maximum forward travel distance and can no longer be moved forward as shown in Fig. 3. Through this process, the propeller 300 reaches a point that is spaced forward from the opening section O of the housing 100, whereby the propeller is tilted upwards at the corresponding point, thereby minimizing the loss of thrust through the boom or wing during the lift-up process. If the actuator 700 continues to be actuated, as in Fig. 4, the forward movements of the upper connecting element 540 are restricted, which is why the sections of the lower connecting element 520 are articulated and folded, causing the propeller 300 to perform a tilting operation by being directed upwards. In the present manner, since the propeller 300 is tilted after being moved forward, the loss of thrust is reduced, thereby reducing the weight and manufacturing costs of the aircraft, since both the forward movement and the rotation of the aircraft are realized by an actuator 700. Since the upper connecting element 540 and the lower connecting element 520 support the propeller 300, the supporting force of the propeller 300 is also increased, so that a stable flight can be achieved when the propeller 300 is raised. Fig. 5 shows a state in which the aircraft A is in cruise flight according to the exemplary embodiment of the present invention when the propeller 300 is tilted downwards, while Fig. 6 shows a state in which the aircraft A experiences a lift motion when the propeller 300 is tilted upwards. According to the tilting system for an aircraft propeller of the present invention, the propeller can not only perform a tilting operation about a single axis, but also perform forward / backward movements during the tilting, suppressing a reduction in lift thrust by a wing or boom, and maintaining stiffness by using a single actuator as in a conventional system. For the sake of clarity and precise definition in the accompanying claims, the terms "upper", "lower", "inner", "outer", "above", "below", "upwards", "downwards", "front", "backwards", "within", "outside", "inwards", "outwards", "internal", "external", "inside", "outside", "forwards", and "backwards" are used to describe features of the exemplary embodiments with reference to the positions of these features shown in the figures. It is further understood that the term "connect" or its derivatives refer to both direct and indirect connections.

Claims

Tilting system for an aircraft propeller (A), wherein the tilting system comprises: a housing (100) with an interior and with an opening section (O) at an end section of the housing (100); a propeller (300) which is provided in front of the opening section (O) of the housing (100) and is configured to be tilted selectively with respect to the housing (100); a connecting element assembly (500), wherein a first end section of the connecting element assembly (500) is coupled to the housing (100) and a second end section of the connecting element assembly (500) is coupled to the propeller (300) and is configured to tilt the propeller (300) up or down when the connecting element assembly (500) is extended from or retracted into the housing (100); and an actuator (700) that is coupled and formed with the connecting element arrangement (500),to provide energy for extending or retracting the connecting element assembly (500), wherein the connecting element assembly (500) comprises an upper connecting element (540) and a lower connecting element (520), the length of the lower connecting element (520) being greater than the length of the upper connecting element (540), and wherein the lower connecting element (520) comprising at least a portion connected to a hinge (522) which is connected to the actuator (700), wherein a forward movement of the upper connecting element (540) is limited by a stop element (542) which is arranged in the housing (100) at a point of maximum forward movement, and wherein the actuator (700) is coupled to the lower connecting element (520), and wherein the lower connecting element (520) is provided with a cylinder,and wherein at least one part of the lower connecting element (520) is moved rearward into the cylinder or forward to an outside of the cylinder. Tilting system according to claim 1, wherein the housing (100) is a boom or a wing of the aircraft (A). Tilting system according to claim 1, wherein the propeller (300) puts the aircraft (A) into a lifting motion when the propeller (300) is tilted upwards, and wherein the propeller (300) puts the aircraft into a cruising motion when the propeller (300) is tilted downwards. Tilting system according to claim 1, wherein the propeller (300) closes the opening section (O) of the housing (100) when the propeller (300) is tilted downwards. Tilting system according to claim 1, wherein the propeller (300) opens the opening section (O) of the housing (100) when the propeller (300) is tilted upwards with respect to a longitudinal axis of the housing (100). Tilting system according to claim 5, wherein the propeller (300) opens the opening section (O) of the housing (100) when the propeller (300) is tilted upwards, and wherein the propeller (300) is arranged perpendicular to the longitudinal axis of the housing (100). Tilting system according to claim 1, wherein the connecting element arrangement (500) is received inside the housing (100) when the propeller (300) is tilted downwards, and wherein the connecting element arrangement (500) is partially exposed to the outside through the opening section (O) when the propeller (300) is tilted upwards. Tilting system according to claim 1, wherein a first end section of the upper connecting element (540) is pivotably connected to the propeller (300) and a second end section of the upper connecting element (540) is slidably coupled to the housing (100) through the opening section (O) of the housing (100), wherein at least a part of the lower connecting element (520) comprises a first connecting element, the first end section of which is pivotably connected to the propeller (300), and a second connecting element, and wherein a first end of the second connecting element is pivotably connected to a second end section of the first connecting element and a second end section of the second connecting element is slidably engaged with the actuator (700) through the opening section (O) of the housing (100). Tilting system according to claim 1, wherein the actuator (700) moves the upper connecting element (540) and the lower connecting element (520) in a first predetermined direction in a longitudinal direction of the housing (100), wherein the upper connecting element (540) and the lower connecting element (520) are moved forward together to tilt the propeller (300), wherein the lower connecting element (520) is moved further forward after the upper connecting element (540) has been moved completely forward, and wherein at least a part of the lower connecting element (520) is moved with respect to the hinge (524) to lift the propeller (300) in order to tilt the propeller (300). Tilting system according to claim 1, wherein the actuator (700) moves the upper connecting element (540) and the lower connecting element (520) in a second predetermined direction in a longitudinal direction of the housing (100), tilting the propeller (300) downwards, moving the lower connecting element (520) backwards into the housing (100), and wherein at least one part is arranged linearly while the upper connecting element (540) and the lower connecting element (520) are moved backwards to tilt the propeller (300). Tilting system according to claim 1, wherein the propeller (300) closes the opening section (O) of the housing (100) when it is tilted downwards, and wherein the propeller (300) is rotated upwards while being moved forwards from the opening section (O) of the housing (100) when it is tilted upwards.

Images