Transmission assembly comprising a transmission member and an oil distribution system
A transmission assembly including a transmission member and an oil distribution system. The transmission member includes a rotary pivot, and a pivot portion for pivoting about the rotary pivot; the oil distribution system is to receive oil feed and to transfer it to an oil reception chamber of the rotary pivot; the rotary pivot includes injection orifices putting the oil reception chamber into fluid flow communication with the gap between the rotary pivot and the pivot portion to form a fluid bearing; and the transmission assembly is for injecting oil into the gap at a first pressure into an outer portion of the gap, and at a second pressure into an inner portion of the gap, the second injection pressure being different from the first injection pressure.
1. A transmission assembly comprising a transmission member and an oil distribution system suitable to be housed in a casing having at least one oil feed;
wherein the transmission member includes at least one rotary pivot suitable for turning about an axis of rotation, and a pivot portion suitable for pivoting about the rotary pivot;
wherein the oil distribution system is configured to receive oil under pressure from the oil feed and to transfer it to at least one oil reception chamber of the rotary pivot;
wherein said rotary pivot includes a first oil reception chamber in a fluid flow communication with an outer portion of a gap between the rotary pivot and the pivot portion facing away from the axis of rotation via at least one first injection orifice, and a second oil reception chamber, distinct from the first oil reception chamber, in fluid flow communication with an inner portion of the gap facing the axis of rotation via at least one second injection orifice, so as to form a fluid bearing; and
wherein the transmission assembly is suitable for injecting oil into said gap at a first injection pressure into the outer portion of the gap, and at a second injection pressure into the inner portion of the gap facing towards the axis of rotation, the second injection pressure being different from the first injection pressure, the transmission assembly comprising both a first oil flow path opening via at least the first injection orifice into the outer portion of the gap, and a second oil flow path, distinct from the first oil flow path, opening via at least the second injection orifice into the inner portion of the gap.
2. The assembly according to claim 1 , wherein the second injection pressure is greater than the first injection pressure.
3. The assembly according to claim 1 , further including a computer configured to adjust the pressure of the first and/or second fluid flow paths as a function of the speed of rotation of the rotary pivot about the axis of rotation.
4. The assembly according to claim 3 , wherein the computer is configured to apply a control relationship whereby the pressure difference between the first and second injection pressures compensates at least 70% of the oil pressure difference between the inner and outer portions of the gap as caused by centrifugal volume forces during rotation of the rotary pivot.
5. The assembly according to claim 1 , having a first oil feed put under pressure by a first pump and feeding the first flow path, and a second oil feed put under pressure by a second pump and feeding the second oil flow path.
6. The assembly according to claim 5 , wherein the oil distribution system comprises a rotary portion having a first oil transfer chamber provided with at least one first feed orifice configured to receive oil from the first oil feed, and a second oil transfer chamber provided with at least one second feed orifice configured to receive oil from the second oil feed;
further comprising a first connection duct putting the first oil transfer chamber into fluid flow communication with the first oil reception chamber, and a second connection duct putting the second oil transfer chamber into fluid flow communication with the second oil reception chamber.
7. The assembly according to claim 1 , wherein the rotary pivot has a plurality of first injection orifices arranged symmetrically on either side of a plane containing a pivot axis of the rotary pivot and the axis of rotation of the rotary pivot.
8. The assembly according to claim 1 , wherein the rotary pivot includes injection orifices possessing flow sections that are different.
9. The assembly according to claim 1 , wherein the transmission member is a speed-reduction gear having an epicyclic gear train including a planet carrier; and
wherein said planet carrier possesses a plurality of spindles constituting rotary pivots, each carrying a planet gear forming a pivot portion.
10. A turbine engine including a transmission assembly according to claim 1 .