The present invention relates to the general field of cooling a turbomachine rotor disk that is located downstream from the cone for driving the disk in rotation. The invention relates more precisely to a device for cooling the slots in such a disk that have the blades mounted therein.
One of the fields of application of the invention is that of low-pressure turbines for aviation turbomachines of the bypass and two-spool type.
Each stage of the low-pressure turbine of a turbomachine is made up of a nozzle formed by a plurality of stationary vanes placed in a flow passage, and a rotary wheel placed behind of the nozzle and formed by a plurality of movable blades likewise placed in the flow passage and mounted via their roots in slots in a rotor disk. The rotor disks of the turbine are generally assembled to one another by means of rings that are fastened together by bolted connections passing through fastener flanges. The resulting disk assembly is itself connected to a turbine shaft via a cone in order to be driven in rotation.
In operation, the flow passage through the low-pressure turbine passes gas at a temperature that is very high. In order to avoid damaging the rotor disks and the blades mounted thereon, it is known to cool these parts by causing cool air to flow into the slots of the rotor disks. For this purpose, one of the known solutions consists in taking cooler air (for example from the high-pressure compressor of the turbomachine) and taking it via a cooling circuit to the slots of the rotor disks. For example, the air that is taken may be conveyed to the slots of the disks by passing via notches formed in the fastener flanges of the ring of the disk between the bolted connections. Reference may be made to document EP 2 009 235, which describes an example of such a cooling device.
Unfortunately, that type of cooling device is not applicable to all existing low-pressure turbines. In particular, it is not always possible to have recourse to a cooling device of the kind described above for cooling the disk that is situated directly downstream from the cone for driving the disks in rotation, because of leaks appearing at the fastener flanges.