Aircraft

Patent metadata

Field	Value
Publication number	US-2022073201-A1
Application number	US-201917414499-A
Country	US
Kind code	A1
Filing date	Nov 28, 2019
Priority date	Dec 21, 2018
Publication date	Mar 10, 2022
Grant date	—

Abstract

An aircraft is described comprising: a support element; a shaft rotating about an axis; a pair of oblique rolling bearings mounted so as to couple the shaft to the support element (rotatingly about the axis; the rolling bearings comprising: respective first races cooperating radially in contact with a first component (defined by one from the support element and the shaft; respective second races cooperating radially in contact with a second component (defined by the other from the support element and the shaft; and respective pluralities of rolling elements adapted to roll on the first and second races; the aircraft further comprises a pair of preloaded elastic members, which couple the first races to the first component respectively, axially and in an elastically yielding manner.

First claim

1 . An aircraft ( 1 ) comprising:
a fuselage ( 2 ) with a first longitudinal extension axis (A) between a nose ( 2 a ) and a tail portion ( 2 b ) opposite along said first longitudinal extension axis (A); a pair of half-wings ( 3 ) extending in a cantilever fashion from respective opposite sides of said fuselage ( 2 ) and transversely to said first longitudinal extension axis (A); a pair of nacelles ( 4 ); and a pair of rotors ( 5 );
each said rotor ( 5 ) comprising, in turn:
a motor ( 6 );
a drive shaft ( 7 ) roatable about a second axis (B);
a hub ( 8 ) dragged, in use, into rotation by said drive shaft ( 7 );
a plurality of blades ( 9 ), which are articulated on said hub ( 8 );

said aircraft ( 1 ) further comprising a transmission ( 10 ) which transmits, in use, the power from said motor ( 6 ) to said drive shaft ( 7 );
said transmission ( 10 ) being a gear reducer and comprising:
an external support casing ( 11 );
an input shaft ( 12 , 12 ′) supported by said external casing ( 11 ) and connected to said motor ( 6 ); and
an output shaft ( 13 ) supported by said external casing ( 11 ) and connected to said drive shaft ( 7 );
said external casing ( 11 ) comprising a support element ( 16 ; 16 ′);
said input shaft ( 12 ; 12 ′) rotating, in use, about a third axis (E, E′);
said transmission ( 10 ) comprising a first coupling assembly ( 14 ) for coupling said input shaft ( 12 ) to said casing ( 11 );
said first coupling assembly ( 14 ) comprising a pair of oblique first rolling bearings ( 17 ; 17 ′) mounted so as to couple said input shaft ( 12 ; 12 ′) to said support element ( 16 ; 16 ′) in a rotating manner about said axis (E, E′);
said first rolling bearings ( 17 ; 17 ′) comprising:
respective first races ( 18 , 19 ; 18 ′, 19 ′) cooperating radially in contact with a first component ( 16 , 12 ; 16 ′, 12 ′) defined by one from said support element ( 16 ; 16 ′) and said input shaft ( 12 ; 12 ′);
respective second races ( 19 , 18 ; 19 ′, 18 ′) cooperating radially in contact with a second component ( 12 , 16 ; 12 ′, 16 ′) defined by the other from said support element ( 16 ; 16 ′) and said input shaft ( 12 ; 12 ′); and
respective pluralities of rolling elements ( 20 ; 20 ′) adapted to roll on said first and said second races ( 18 , 19 ; 18 ′ 19 ′; 19 , 18 ; 19 ′, 18 ′);

characterized by further comprising a pair of preloaded elastic members ( 21 ; 21 ′), which couple said first races ( 18 , 19 ; 18 ′, 19 ′) to said first component ( 16 , 12 ; 16 ′, 12 ′) respectively, axially and in an elastically yielding manner;
wherein said couple of elastic members ( 21 ; 21 ′) is arranged axially between said first races ( 18 , 19 ; 18 ′, 19 ′);
wherein said first component ( 16 , 12 ; 16 ′, 12 ′) defines a pair of first shoulders ( 33 ; 33 ′) arranged axially between said pair of preloaded elastic members ( 21 ; 21 ′); said preloaded elastic members ( 21 ; 21 ′) coupling said first races ( 18 , 19 ; 18 ′, 19 ′) to said first shoulders ( 33 ; 33 ′) respectively, in an elastically yielding manner in an axial direction;
wherein said first component ( 16 , 12 ; 16 ′, 12 ′) defines a pair of second shoulders ( 35 ; 35 ′) respectively axially facing said first races ( 18 , 19 ; 18 ′, 19 ′), so as to define respective axial end-stops for said first races ( 18 , 19 ; 18 ′, 19 ′);
said output shaft ( 13 ) being coupled to said casing ( 11 ) by means of a second coupling assembly ( 110 ), which comprises at least one second rolling bearing ( 111 , 112 );
said first races ( 18 , 19 ; 18 ′, 19 ′) being configured to float, in use, along said third axis (E, E′) in response to the application of an axial load on said first component ( 16 , 12 ; 16 ′, 12 ′);
said transmission ( 30 ) further comprising a third coupling assembly ( 101 ) for rotatably supporting said input shaft ( 12 , 12 ′) with respect to said casing ( 11 );
said third coupling assembly ( 101 ) comprising at least one third radial rolling bearing ( 102 , 103 ) configured to transfer the whole radial loads from said input shaft ( 12 , 12 ′) to said casing ( 11 );
said oblique first rolling bearings ( 17 , 17 ′) being configured to transfer an axial load from said input shaft ( 12 , 12 ′) and said casing ( 11 ) and being operated to transfer only said axial load, in use.

2 . An aircraft according to claim 1 , wherein said first races ( 18 , 19 ; 18 ′, 19 ′) are made of a first material and said rolling elements ( 20 ; 20 ′) are made of a second material different from said first material and having a coefficient of thermal expansion different from that of said first material.

3 . An aircraft according to claim 1 , wherein said first races ( 18 , 19 ; 18 ′, 19 ′) are arranged axially between said elastic members ( 21 ; 21 ′).

4 . An aircraft according to claim 1 , wherein said first component ( 16 , 12 ; 16 ′, 12 ′) defines a shoulder member ( 30 ; 30 ′) comprising a base ( 34 ; 34 ′) and a projection ( 32 ; 32 ′) which protrudes radially towards said second component ( 12 , 16 ; 12 ′, 16 ′), defining a pair of slots ( 31 ; 31 ′) with said base ( 34 ; 34 ′) respectively engaged by said preloaded elastic members ( 21 ; 21 ′); said base ( 34 ; 34 ′) and said projection ( 32 ; 32 ′) defining said pair of second shoulders ( 35 ; 35 ′) and said pair of first shoulders ( 33 ; 33 ′) respectively.

5 . An aircraft according to claim 1 , wherein each of said preloaded elastic members ( 21 ; 21 ′) comprises one or more springs ( 50 ; 51 ;
52 ) arranged in series and each defined by one from:
a disk spring ( 50 );
a helical spring ( 51 ); and
a wave spring ( 52 ).

6 . An aircraft according to claim 1 , wherein:
said first races ( 18 , 19 ; 18 ′, 19 ′) are defined by respective radially external races ( 18 , 18 ′) of said oblique first rolling bearings ( 17 ); and said first component ( 16 , 12 ; 16 ′, 12 ′) is defined by said support element ( 16 , 16 ′); said pair of oblique first rolling bearings ( 17 ) being mounted in a back-to-back configuration.

7 . An aircraft according to claim 1 wherein:
said first races ( 18 , 19 ; 18 ′, 19 ′) are defined by respective radially internal races ( 19 , 19 ′) of said oblique rolling bearings ( 17 ′); and
said first component ( 16 , 12 ; 16 ′, 12 ′) is defined by said input shaft ( 12 ; 12 ′);

said pair of oblique first rolling bearings ( 17 ′) being mounted in a face-to-face configuration

8 . An aircraft according to claim 1 , characterized said third coupling assembly ( 101 ) is axially interposed between said motor ( 6 ) and said first coupling assembly ( 14 ).

9 . An aircraft according to claim 1 , characterized in that said transmission ( 10 ) comprises a helix gearing ( 100 ) for rotatably coupling said first input shaft ( 12 ) and said output shaft ( 13 ).

10 . An aircraft according to claim 1 , characterized in that said third coupling assembly ( 101 ) comprises a pair of said third radial rolling bearings ( 102 , 103 ).

11 . An aircraft according to claim 9 , characterized in that said helix gearing ( 100 ) is axially interposed between said third radial rolling bearing ( 102 , 103 ).

12 . An aircraft according to claim 9 , characterized in that said second coupling assembly ( 110 ) comprises said second rolling bearing ( 111 ) and a fourth rolling bearing ( 112 );
said gearing ( 100 ) being axially interposed between said second rolling bearing ( 111 ) and said fourth rolling bearing ( 112 ); said fourth rolling bearing ( 112 ) being an oblique rolling bearing configured to transmit both

Assignees

• Leonardo Spa

Inventors

• Podda Daniele
• Gabrielli Andrea
• Regonini Roberto
• Montagna Federico
• Poggi Stefano

Classifications

• F16C2326/43

  Aeroplanes; Helicopters · CPC title

• F16C19/543

  in O-arrangement · CPC title

• F16C25/083

  with resilient means acting axially on a race ring to preload the bearing · CPC title

• F16C19/542

  with two rolling bearings with angular contact · CPC title

• F16C19/548

  in O-arrangement · CPC title