Bearing arrangement for a rotating shaft, and turbine engine equipped with such an arrangement

1. A bearing arrangement for a shaft rotating about an axis, comprising:

an outer bearing race;

an inner bearing race including a first half-race fastened to the rotating shaft and a second half-race;

rolling elements arranged between the outer bearing race and the inner bearing race;

a maintaining unit which maintains said two half-races together; and

a retention piece fastened to the rotating shaft and which retains the second half-race,

wherein said maintaining unit breaks or deforms when the bearing is subjected to a misalignment or a moment above a predetermined value, so as to allow an axial displacement of the second half-race with respect to the first half-race, and

wherein the retention piece is a piece of revolution which includes a fastening collar which fastens the retention piece to the rotating shaft, a support ring extending circumferentially which radially supports the second half-race after the axial displacement thereof, a conical body which connects the support ring to the fastening collar, and an axial blocking flange extending radially which blocks the second half-race axially after the axial displacement thereof.

2. The bearing arrangement as claimed in claim 1 , wherein said two half-races are distinct from one another, and

wherein said maintaining unit includes a spacer interposed between the second half-race and the axial blocking flange.

3. The bearing arrangement as claimed in claim 1 , further comprising a rotation stop device which prevents a relative rotation of said second half-race with respect to said support ring after separation.

4. The bearing arrangement as claimed in claim 3 , wherein said rotation stop device comprises a recess in said support ring and a projection on the second half-race.

5. The bearing arrangement as claimed in claim 1 , further comprising at least one elastic member for returning the second half-race toward the first half-race.

6. A turbine engine which comprises at least one bearing arrangement as claimed in claim 1 .

7. The bearing arrangement as claimed in claim 1 , wherein the axial blocking flange is provided at a downstream end of the support ring.

8. The bearing arrangement as claimed in claim 1 , wherein the first half-race includes a race extension, and the race extension and the fastening collar are bolted to the rotating shaft.

9. A bearing arrangement for a shaft rotating about an axis, comprising:

an outer bearing race;

an inner bearing race including a first half-race fastened to the rotating shaft and a second half-race;

rolling elements arranged between the outer bearing race and the inner bearing race; and

a maintaining unit which maintains said two half-races together,

wherein said maintaining unit being breaks or deforms when the bearing is subjected to a misalignment or a moment above a predetermined value, so as to allow an axial displacement of the second half-race with respect to the first half-race,

wherein said maintaining unit includes a connecting annulus interposed between the two half-races and interconnecting the two half-races such that, before separation, the inner bearing race is a single unit, and

wherein said connecting annulus breaks under tension when the bearing is subjected to a misalignment or a moment above the predetermined value.

10. The bearing arrangement as claimed in claim 9 , wherein said connecting annulus is continuous.

11. The bearing arrangement as claimed in claim 9 , wherein said connecting annulus is discontinuous.

12. A bearing arrangement for a shaft rotating about an axis, comprising:

an outer bearing race;

an inner bearing race including a first half-race fastened to the rotating shaft and a second half-race;

rolling elements arranged between the outer bearing race and the inner bearing race; and

a maintaining unit which maintains said two half-races together,

wherein said maintaining unit being breaks or deforms when the bearing is subjected to a misalignment or a moment above a predetermined value, so as to allow an axial displacement of the second half-race with respect to the first half-race,

wherein said two half-races are distinct from one another, and wherein said maintaining unit includes a spacer interposed between the second half-race and an axial blocking flange, said axial blocking flange being fastened to the rotating shaft, and

wherein said spacer includes a washer with weakness zones which break when the bearing is subjected to a misalignment or a moment above the predetermined value.

13. The bearing arrangement as claimed in claim 12 , wherein said spacer comprises:

a substantially oblique annular body,

a first rim extending radially inward from said body and intended to support said spacer against said second half-race, and

a second rim extending radially outward from said body and intended to support said spacer against said axial blocking flange,

and wherein said body is pierced with holes separated by said weakness zones.

14. The bearing arrangement as claimed in claim 12 or 13 , wherein said weakness zones are designed to break in tension.

15. The bearing arrangement as claimed in claim 12 , wherein said spacer comprises:

an annular body,

first protrusions distributed angularly over said body, extending axially from a first face thereof and intended to support said spacer against said second half-race, and

second protrusions distributed angularly over said body, extending axially from a second face thereof and intended to support said spacer against said axial blocking flange,

and wherein said first protrusions and said second protrusions are separated by zones of the body which constitute said weakness zones.

16. The bearing arrangement as claimed in claim 12 or 15 , wherein said weakness zones are designed to break in bending/shear.