Roller bearing comprising an oil film compression damper of modifiable length
A bearing for a turbine engine includes an oil film compression damper, including an inner sleeve intended to receive an outer ring of a roller bearing, an outer sleeve surrounding the inner sleeve and delimiting with this inner sleeve, an axisymmetric cavity supplied hydraulically in order to form a film of damping oil, this cavity being closed at its ends by two segments. The cavity includes a first portion and a second portion separated from one another by a movable segment able to occupy a closed position in which it forms a controlled sealing barrier between the two portions, and an open position in which the two portions communicate with one another, and in that it is the first portion that is supplied hydraulically to form the film of oil.
1 . A bearing for a turbine engine comprising an oil film compression damper, including an inner sleeve intended to receive an outer ring of a roller bearing, an outer sleeve surrounding the inner sleeve and delimiting with the inner sleeve an axisymmetric cavity supplied hydraulically in order to form a film of damping oil, the ends of the cavity being closed by two segments, wherein the cavity includes a first portion and a second portion separated from one another by a radially movable segment able to occupy a closed position wherein the movable segment forms a controlled sealing barrier between the first and second portions, and an open position wherein the first and second portions communicate with one another, and in that the first portion is supplied hydraulically to form the film of oil.
2 . The bearing according to claim 1 , comprising a circumferential groove formed at an inner face of the outer sleeve, wherein the movable segment is retracted in the groove when the movable segment occupies the open position, and wherein the movable segment comes out of the groove to be supported on the outer face of the inner sleeve when the movable segment occupies the closed position.
3 . The bearing according to claim 2 , comprising radial holes passing through an outer face of the outer sleeve and leading to the bottom of the groove, and wherein the movable segment includes a plurality of sectors in an arc of a circle, each sector provided with a pin sliding in a radial hole.
4 . The bearing according to claim 3 , wherein the movable segment is formed of three sectors, each sector having an angular extension of 120 degrees.
5 . The bearing according to claim 3 , comprising an actuator cooperating with each pin to radially move each pin in such a way as to control the movable segment to move the movable segment from the open position to the closed position and vice versa.
6 . The bearing according to claim 3 , comprising a hydraulic or pneumatic control circuit cooperating with each pin to radially move each pin in such a way as to control the movable segment to move the movable circuit from the open position to the closed position and vice versa.
7 . The bearing according to claim 6 , wherein the control circuit includes a circumferential cavity extending into the thickness of the outer sleeve and wherein the ends of each pin lead, the circumferential cavity being supplied hydraulically or pneumatically.
8 . A turbine engine equipped with the bearing according claim 1 .
9 . A turbojet engine comprising the turbine engine according to claim 8 .