Abstract: An aircraft undercarriage is provided (1). The undercarriage (1) includes a rocker lever (2) having a first end zone (2a) for fastening to at least one point of the structure of the aircraft and a second end zone (2b) connected via a swivel (3) to twin wheels (4) including a wheel axle (9) connecting together two landing wheels (R1, R2). The swivel (3) includes a first portion (3b) that is fastened to the second end zone (2b) of the rocker lever (2) and a second portion (3c) being free to swivel relative to the first portion (3b) about a swivel axis (A1, A2) of the swivel (3). the second portion (3c) is connected to the wheel axle (9) of the twin wheels (4). In addition, the connection between the second portion (3c) of the swivel (3) and the wheel axle (9) includes a hinge (6).

Abstract: An energy absorber system (10) provided with a shock absorber (11) extending from a first end (12) suitable for being connected to a rocker arm (5) of an undercarriage (3) housed in a wheel bay (4), towards a second end (13). In addition, the system includes a fitting (20) connected to said second end (13), and guide means (30) for guiding said fitting (20) in translation that is suitable for being fastened to a flank (4?) of said wheel well (4), said system (10) including deformable energy absorber means (40) fastened to said fitting (20) and suitable for being fastened to a structure (4?) of said bay (4) and also to fusible retention means (50) suitable for fastening said fitting (20) to said flank (4?), said fusible retention means (50) rupturing from a predetermined threshold in order to allow said fitting (20) to move under guidance from said guide means (30) so as to deform said energy absorber means (40).

Abstract: A damper (1) is provided with a body (2) which surrounds an annular compression chamber (3), the damper (1) being furnished with at least one pneumatic compensation chamber (30, 40) and a control piston (4) that can move relative to the body (2), the control piston (4) having a rod (5) which protrudes from the body (2) and a head (6) which slides in the compression chamber (3). The damper is notable in that, the compression chamber (3) comprising a variable-section radial opening (8), the damper (1) is provided with a hydraulic compensation chamber (10) which receives a first fluid expelled from the annular compression chamber (3) via the variable-section radial opening (8) when the control piston (4) moves.

Abstract: An energy absorber system (10) provided with a shock absorber (11) extending from a first end (12) suitable for being connected to a rocker arm (5) of an undercarriage (3) housed in a wheel bay (4), towards a second end (13). In addition, the system includes a fitting (20) connected to said second end (13), and guide means (30) for guiding said fitting (20) in translation that is suitable for being fastened to a flank (4?) of said wheel well (4), said system (10) including deformable energy absorber means (40) fastened to said fitting (20) and suitable for being fastened to a structure (4?) of said bay (4) and also to fusible retention means (50) suitable for fastening said fitting (20) to said flank (4?), said fusible retention means (50) rupturing from a predetermined threshold in order to allow said fitting (20) to move under guidance from said guide means (30) so as to deform said energy absorber means (40).

Abstract: A retraction cylinder (20) makes it possible to retract a leg (10) of a rotorcraft landing gear, the retraction cylinder (20) comprising a retraction chamber (33) and an extension chamber (34) separated by a head (26) of a piston (25), the piston (25) sliding in a cylindrical sheath (35). In addition, the retraction cylinder (20) comprises a return element (23) and a control chamber (22) furnished with a first fluid, this control chamber (22) being separated from the return element (23) by a movable release member (24), the movable release member (24) sliding so that the retraction cylinder (20) fulfils a damping function when a control pressure exerted by the first fluid on the movable release member (24) is greater than a return pressure exerted by the return element (23).

Abstract: The invention relates to an aircraft undercarriage (1), the undercarriage (1) comprising a rocker lever (2) having a first end zone (2a) for fastening to at least one point of the structure of the aircraft and a second end zone (2b) connected via a swivel (3) to twin wheels (4) comprising a wheel axle (9) connecting together two landing wheels (R1, R2), said swivel (3) presenting a first portion (3b) that is fastened to said second end zone (2b) of the rocker lever (2) and a second portion (3c) presenting freedom to swivel relative to the first portion (3b) about a swivel axis (A1, A2) of said swivel (3), said second portion (3c) being connected to said wheel axle (9) of the twin wheels (4). In addition, the connection between the second portion (3c) of said swivel (3) and said wheel axle (9) presents a hinge (6).

Abstract: A damper (1) is provided with a body (2) which surrounds an annular compression chamber (3), the damper (1) being furnished with at least one pneumatic compensation chamber (30, 40) and a control piston (4) that can move relative to the body (2), the control piston (4) having a rod (5) which protrudes from the body (2) and a head (6) which slides in the compression chamber (3). The damper is notable in that, the compression chamber (3) comprising a variable-section radial opening (8), the damper (1) is provided with a hydraulic compensation chamber (10) which receives a first fluid expelled from the annular compression chamber (3) via the variable-section radial opening (8) when the control piston (4) moves.

Abstract: A retraction cylinder (20) makes it possible to retract a leg (10) of a rotorcraft landing gear, the retraction cylinder (20) comprising a retraction chamber (33) and an extension chamber (34) separated by a head (26) of a piston (25), the piston (25) sliding in a cylindrical sheath (35). In addition, the retraction cylinder (20) comprises a return element (23) and a control chamber (22) furnished with a first fluid, this control chamber (22) being separated from the return element (23) by a movable release member (24), the movable release member (24) sliding so that the retraction cylinder (20) fulfils a damping function when a control pressure exerted by the first fluid on the movable release member (24) is greater than a return pressure exerted by the return element (23).