Device for centring and rotationally guiding a turbomachine shaft comprising means for an axial retention of outer ring of a bearing

Abstract

A device for centring and rotationally guiding a turbomachine shaft, including a rolling bearing including an outer ring, a bearing mount, a band interposed between the outer ring and the bearing mount and a device for connecting the outer ring to the bearing mount, including a device for the axial retention of the outer ring including an axial thrust flange downstream of and in contact with the fixing flange of the connecting device, and including a fixing hole for fixing together the fixing flange, the bearing mount and the axial thrust flange, which latter further includes a lug extending between two successive tabs of the elastically deformable device.

Claims

1. A device for centring and rotatably guiding a shaft of a turbomachine, comprising: a rolling bearing comprising an outer ring, a bearing support surrounding the outer ring, a shrink ring interposed between the outer ring and the bearing support, connection means for connecting the outer ring to the bearing support, the connection means comprising an annular fastening clamp mounted to the bearing support, and elastically deformable means linking the outer ring to the fastening clamp and comprising at least one annular row of upstream opened U-shaped tabs, and retaining means for axially retaining the outer ring in case of a rupture of said elastically deformable means, wherein the retaining means includes at least one axial stop clamp extending on an angular sector about an axis of revolution of the rolling bearing, positioned downstream of and in contact with the fastening clamp, and said at least one axial stop clamp includes at least one fastening hole cooperating with a port of the fastening clamp for fastening together the fastening clamp, the bearing support, and said at least one axial stop clamp with at least one fastening member, and at least one axial holding stud radially extending toward the axis of revolution of the rolling bearing between two successive tabs of the elastically deformable means.

2. The device according to claim 1, further comprising a plurality of axial stop clamps distributed on the fastening clamp about the axis of revolution of the rolling bearing.

3. The device according to claim 1, wherein said at least one axial stop clamp includes at least two axial holding studs circumferentially spaced apart and extending toward the axis of revolution of the rolling bearing.

4. The device according to claim 1, wherein said at least one axial stop clamp includes at least two fastening holes circumferentially spaced apart and each located at a circumferential end of said at least one axial stop clamp.

5. The device according to claim 1, wherein said at least one axial stop clamp includes a central portion recessed so as to decrease a mass of said at least one axial stop clamp.

6. The device according to claim 5, wherein said at least one axial stop clamp includes, at the recessed central portion, at least one ventilation hole.

7. The device according to claim 1, wherein a radial end of said at least one stud, located between two successive tabs, has one or more relief ground parts to avoid any collision risk.

8. The device according to claim 1, wherein a play available between a stud and a tab adjacent to the stud is higher than a radial displacement of the outer ring.

9. The device according to claim 1, wherein the elastically deformable means includes two annular rows of tabs.

10. A turbomachine, comprising at least one device according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood upon reading the following detailed description, of an example of a non-limiting implementation thereof, as well as upon examining the schematic and partial figures of the appended drawing, in which:

(2) FIG. 1 is a half-axial cross-section schematic view of an example of device for centring and rotatably guiding a shaft of a turbomachine, according to prior art,

(3) FIG. 2 is a view at a greater scale of the detail II of FIG. 1,

(4) FIG. 3 illustrates, partially and in perspective, another example of device for centring and rotatably guiding a shaft of a turbomachine, according to prior art, including two annular rows of tabs,

(5) FIG. 4 is a half-axial cross-section schematic view of an example of device for centring and rotatably guiding a shaft of a turbomachine, according to the invention,

(6) FIG. 5 illustrates, partially and in perspective, an example of axial stop clamp of a device according to the invention, fastened to the fastening clamp and comprising studs extending between the tabs of the device,

(7) FIG. 6 illustrates, in an isolated way and in perspective, the axial stop clamp of FIG. 5,

(8) FIG. 7 represents, in a front face, the device of FIG. 5 comprising three axial stop clamps fastened to the fastening clamp of the device, and

(9) FIG. 8 is a partial perspective enlarged view of the device of FIG. 5 enabling the extent of the studs between the tabs of the device to be better viewed.

(10) Throughout these figures, identical references can designate identical or analogous elements.

(11) In addition, the different parts represented in the figures are not necessarily drawn to a uniform scale, to make the figures more readable.

DETAILED DESCRIPTION OF THE INVENTION

(12) It is to be noted that, throughout the description, the directions “upstream” and “downstream” are defined with respect to a general gas flow direction parallel to an axis 13 of the shaft 12 corresponding to an axis of the turbomachine, and the radial “inwardly” and “outwardly” directions are defined with respect to the axis 13.

(13) FIGS. 1 to 3 have already been described in the part relative to the state of prior art and to the technical context of the invention.

(14) An example of device 10 for centring and rotatably guiding a shaft 12 of a turbomachine in accordance with the invention will now be described in reference to FIGS. 4 to 8. It is to be noted that the elements previously described in connection with FIGS. 1 to 3 in the part relative to prior art and to the technical context of the invention are not described again. Of course, except for the retention means specific to prior art comprising in particular a retention ring 72 and pins 60, all of the characteristics previously described in connection with FIGS. 1 to 3 can be incorporated to a device 10 in accordance with the invention.

(15) Thus, the device 10 includes a rolling bearing comprising an outer ring 18, a bearing support 20 surrounding the outer ring 18, a shrink ring 28 interposed between the outer ring 18 and the bearing support 20, and connection means 29 for connecting the outer ring 18 to the bearing support 20.

(16) These connection means 29 comprise an annular fastening clamp 30 mounted to the bearing support 20 and elastically deformable means 32 linking the outer ring 18 to the fastening clamp 30, comprising at least one annular row of upstream open U-shaped tabs 34.

(17) In addition, the device 10 includes retention means for axially retaining the outer ring 18 in case of rupture of the elastically deformable means 32.

(18) In accordance with the invention, these retention means include an axial stop clamp 100, here three axial stop clamps not evenly distributed about the axis of revolution 13 of the outer ring 18.

(19) These axial stop clamps 100 each extend on an angular sector about the axis of revolution 13 of the outer ring 18.

(20) They are positioned downstream and in contact with the fastening clamp 30. In addition, they each include fastening holes 101 cooperating with a port 102 of the fastening clamp 30 for fastening together the fastening clamp 30, the bearing support 20 and the axial stop clamp 100 through a fastening bolt 31.

(21) More precisely, each axial stop clamp 100 includes two fastening holes 101 circumferentially spaced apart and each located at a circumferential end of the axial stop clamp 100, as is in particular visible in FIG. 6.

(22) Further, each axial stop clamp 100 includes studs 103 (or fingers), here two studs 103 for each clamp 100, radially extending to the axis of revolution 13 of the outer ring 18 between two successive tabs 34 of the elastically deformable means 32, as is in particular visible in FIGS. 5 and 6.

(23) Moreover, each axial stop clamp 100, as shown in particular in FIG. 6, includes a central portion 104 forming a lightening pocket, located between both studs 103, which is recessed in a non through way so as to decrease the mass of the axial stop clamp 100. At this recessed central portion 104, a plurality of ventilation holes 105, for example four ventilation holes 105 in this example, are formed.

(24) In addition, as is in particular visible in FIG. 8, the radial end of each stud 103, located between two successive tabs 34, has relief ground parts 106 made so as to avoid any collision risk.

(25) It should be further noted that, as illustrated in FIG. 8, the play J available between a stud 103 and a tab 34 adjacent to the stud 103 is advantageously higher than the radial displacement of the outer ring 18 for absorption optimisation reasons.

(26) Consequently, displacing of the axial stop function downstream of the fastening clamp 30, provided by the invention through the use of axial stop clamps 100, enables the operation of the bearing to be optimised and makes it possible to fulfil at least partly the problems previously raised in view of prior art.

(27) Of course, the invention is not limited to the exemplary embodiment just described. Various modifications can be provided thereto by those skilled in the art.