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EP-4428031-B1 - LANDING GEAR FOR A VERTICAL TAKE-OFF AND LANDING AIRCRAFT

EP4428031B1EP 4428031 B1EP4428031 B1EP 4428031B1EP-4428031-B1

Inventors

  • BRESCIANI, Luca Mario
  • Pestal, Dieter
  • BORN, Sebastian
  • BERGERON, RICHARD

Dates

Publication Date
20260513
Application Date
20230306

Claims (14)

  1. Landing gear (10) for a vertical take-off and landing aircraft (100), comprising a wheel (20), a shock absorber (30) with an absorber connection (32) to connect to a fuselage (110) of the aircraft (100) and at least one attachment lever (40) with a lever connection (42) to connect to the fuselage (110) of the aircraft (100) spaced apart from the absorber connection (32), the wheel (20) being attached to the attachment lever (40) spaced apart from the lever connection (42), wherein the shock absorber (30) is connected to the wheel (20) directly or indirectly via a wheel connection (34) to provide a load path (LP) for vertical load from the wheel (20) to the absorber connection (32), characterised in that the shock absorber (30) comprises a fuse pin (36) at the wheel connection (34), said fuse pin (36) having a predetermined breaking load to break and release the connection at the wheel connection (34) and the attachment lever (40) comprises a rotary bearing (41) providing a folding movement for the wheel (20) from an extended landing position (ELP) into a crash position (CP) when the fuse pin (36) breaks.
  2. Landing gear (10) according to claim 1, wherein the wheel (20) has a wheel axis (22) located behind the wheel connection (34) of the shock absorber (30) in forward direction (FD).
  3. Landing gear (10) according to any of the preceding claims, wherein the wheel (20) has a wheel axis (22) located behind the absorber connection (32) in forward direction (FD).
  4. Landing gear (10) according to any of the preceding claims, wherein the wheel (20) has a wheel axis (22) located behind the lever connection (42) in forward direction (FD).
  5. Landing gear (10) according to any of the preceding claims, wherein the wheel connection (34) is located behind the absorber connection (32) in forward direction (FD).
  6. Landing gear (10) according to any of the preceding claims, wherein the wheel connection (34) and/or the absorber connection (32) are located behind the lever connection (42) in forward direction (FD).
  7. Landing gear (10) according to any of the preceding claims, wherein the lever connection (42), the absorber connection (32) and the wheel connection (34) are located in a plane parallel or substantially parallel to the forward direction (FD).
  8. Landing gear (10) according to any of the preceding claims, wherein the attachment lever (40) has a straight extension form the lever connection (42) to a wheel axis (22) of the wheel (20), in particular wherein the wheel connection (34) of the shock absorber (30) is connected to the attachment lever (40) between the lever connection (42) and the wheel axis (22).
  9. Landing gear (10) according to any of the preceding claims, wherein the rotary bearing (41) of the attachment lever (40) has a bearing axis (43) perpendicular to a forward direction (FD) and/or a wheel axis (22) of the wheel (20).
  10. Landing gear (10) according to any of the preceding claims, wherein the rotary bearing (41) of the attachment lever (40) provides the folding movement additionally between the extended landing position (ELP) and a compressed landing position (CLP), in particular wherein an absorbing direction (AD) of the folding movement is parallel or coaxial with a crash direction (CD) of the folding movement.
  11. Landing gear (10) according to any of the preceding claims, wherein the fuse pin (36) is located in a pin area (37) of the shock absorber (30), wherein the pin area (37) is provided with at least one guiding surface (50) and/or the attachment lever (40) is provided with counter-guiding surfaces (52) to provide a guided movement of the shock absorber (30) after the breaking of the fuse pin (36).
  12. Landing gear (10) according to claim 11, wherein the guiding surfaces (50) comprise guiding sidewalls (51) and/or the counter-guiding surfaces (52) comprise counter-guiding sidewalls (53) providing side engagement.
  13. Landing gear (10) according to any of the claims 11 or 12, wherein the guiding surfaces (50) and/or the counter-guiding surfaces (52) extend in the plane of the folding movement.
  14. Aircraft (100) for vertical take-off and landing, comprising at least one landing gear (10) according to claims 1 to 13 being connected to a fuselage (110) of the aircraft (100).

Description

The present invention is related to a landing gear for a vertical take-off and landing aircraft as well as an aircraft equipped with at least one of those landing gears. It is known that aircrafts need a landing gear provided with at least one wheel or any other element that allows moving of the aircraft to take-off and land as well as to move while on ground. Such a landing gear usually provides shock absorbing functionality for the case that during the landing process a vertical force is applied to the landing gear that needs to be absorbed before it reaches the fuselage of the aircraft. For regular aircrafts as well as for vertical take-off and landing aircrafts one issue is to ensure that in a crash situation, when the vertical load of a landing situation increases significantly, this is not resulting in any harm for the interior and the passengers inside of the aircraft. For regular aircrafts as well as for vertical take-off and landing aircrafts used for passenger transport a so-called piercing of the cabin needs to be avoided by any means. Since the location of the landing gear below the cabin of such an aircraft is preferred in terms of optimized aerodynamics as well as reduced weight and stability in ground operations the risk of piercing the cabin and the risk of parts of the landing gear entering the cabin in general exists. Of course, also other positions for the landing gear are possible with the risk of damaging any components above, for example a wing, a fuel tank or the like. Present technologies usually comprise either a piercing protection for example a rigid steel plate between the landing gear and the cabin to avoid and/or reduce the piercing risk. Such an additional steel protection increases the weight and thereby the energy consumption during use of the aircraft. The other possibility to avoid the risk of piercing the cabin is to move the landing gear to a position which is spaced apart from the cabin and thereby in a crash situation the piercing will not be close to the cabin but for example would still damage the wings or other close components. This means that either additional weight and complexity or a reduced freedom of construction needs to be applied to reduce or even avoid the risk parts of the landing gear piercing the cabin of an aircraft. US8439304, US7066429, US6679452, US 8539843, KR20120044602 disclose landing gears comprising fuse pins configured to break following an overload at landing. It is an object of the present invention to overcome the disadvantages described above at least partly. In particular it is an object of the present invention to provide an easy and cost-efficient solution to avoid a piercing of the cabin in an overload or crash situation and thereby increase the cabin safety. Aforesaid problem is solved by a landing gear with the features of independent claim 1 as well as an aircraft with the features of claim 14. Technical features mentioned in the sub claims can be combined with the features of the independent claims. According to the present invention the landing gear is provided with two general functionalities. One is the absorbing functionality which is used in a regular landing situation which is described in the following passage. Of course, the inventive landing gear could also be used in an aircraft with regular landing and take-off functionality. Additionally, it has to be noted that a wheel according to the present invention can also be substituted by any other element that allows moving of an aircraft without leaving the scope of the present invention. For example, a skid, a slider or the like could be used as a wheel in the meaning of the present invention. A fuse pin according to the present invention can be constructed in different ways. It could also comprise or be embodied by a lug-element that is deformable and/or can break completely. Also a combination of a deformation that is followed by a full break of the element is covered by the scope of the present invention. The landing gear is usually placed beneath the cabin of the aircraft. Of course, also other positions are possible, for example below the wings. When the aircraft approaches a landing situation it reduces altitude and during the landing process will touch the ground first with the landing gear and particular with the wheel. While the uplifting force generated by rotors and/or by the aerodynamics of wings is further reduced, the aircraft will put its full weight on the wheel and thereby the force along the load path of the landing gear is increased. In particular when there is a hard landing or a quick decrease in altitude this force is higher than the weight load provided by the aircraft itself. All of those additional forces are absorbed by the shock absorber so that the comfort of the passengers inside of the cabin of the aircraft is increased. Again, this is true for a regular aircraft as well as an aircraft for vertical take-off and/or landing. In case of an emerge