Gas turbine engine turbine vane ring arrangement

A vane pack for a gas turbine engine includes an annular arrangement of vanes. A ring is secured around the vanes and extends proud of an axial end of the vanes.

BACKGROUND

This disclosure relates to a gas turbine engine vane arrangement, for example, in a turbine section. More particularly, the disclosure relates to a ring used to secure circumferentially arranged vanes to one another in, for example, a mid-turbine frame.

Gas turbine engines typically include a compressor section, a combustor section and a turbine section. During operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.

Both the compressor and turbine sections may include alternating series of rotating blades and stationary vanes that extend into the core flow path of the gas turbine engine. For example, in the turbine section, turbine blades rotate and extract energy from the hot combustion gases that are communicated along the core flow path of the gas turbine engine. The turbine vanes, which generally do not rotate, guide the airflow and prepare it for the next set of blades.

A mid-turbine frame is arranged axially between high and low turbine sections. One type of mid-turbine frame uses discrete vanes secured circumferentially to one another to provide an integral annular vane pack. The vane pack is reinforced using multiple rings secured to the vanes. An edge of the vane pack is disposed within a pocket of rotating blades of an adjacent turbine stage to provide a seal at the inner flow path. The reinforcement ring at this location is spaced from and outside of the pocket.

SUMMARY

In one exemplary embodiment, a vane pack for a gas turbine engine includes an annular arrangement of vanes. A ring is secured around the vanes and extends proud of an axial end of the vanes.

In a further embodiment of any of the above, the annular arrangement includes vane segments secured to one another circumferentially.

In a further embodiment of any of the above, the ring is secured to the vanes by mechanical elements.

In a further embodiment of any of the above, the mechanical elements include at least one of a braze, a weld and fasteners.

In a further embodiment of any of the above, the ring is secured to the vanes by an interference fit.

In a further embodiment of any of the above, the ring and the vanes include interlocking features that engage one another and are configured to prevent relative axial movement between the ring and the vanes.

In a further embodiment of any of the above, the ring is secured to an inner platform.

In a further embodiment of any of the above, the axial end is a leading edge.

In a further embodiment of any of the above, the ring provides an end configured to provide a seal with an adjacent rotating component.

In a further embodiment of any of the above, the end includes one of an annular pocket and an annular lip.

In another exemplary embodiment, a gas turbine engine includes a compressor section. A combustor is fluidly connected downstream from the compressor section. A turbine section is fluidly connected downstream from the combustor and includes high and low pressure turbine sections. A vane pack is arranged in one of the compressor or turbine sections. The vane pack includes a ring secured around an annular arrangement of vanes and extends proud of an axial end of the vanes to an end. The end interleaves with an adjacent rotating component to provide a seal.

In a further embodiment of any of the above, the vane pack is arranged in the turbine section.

In a further embodiment of any of the above, the rotating components include one of a pocket and a lip. The ring provides the other of the pocket and the lip. The lip is arranged in the pocket to provide the seal.

In a further embodiment of any of the above, the stage of rotating blades is provided by the high pressure turbine section. The vane pack provides a mid-turbine frame.

In a further embodiment of any of the above, the engine static structure supports a sealing ring that engages the reinforcement ring.

In a further embodiment of any of the above, the annular arrangement includes vane segments secured to one another circumferentially.

In a further embodiment of any of the above, the vanes are discrete from one another and hung from engine static structure.

In a further embodiment of any of the above, the reinforcement ring is secured to the vanes by at least one of a mechanical element and an interference fit.

In a further embodiment of any of the above, the reinforcement ring is secured to an inner platform.

In a further embodiment of any of the above, the axial end is a leading edge.

DETAILED DESCRIPTION

A mid-turbine frame57of the engine static structure36is arranged generally between the high pressure turbine54and the low pressure turbine46. The mid-turbine frame57further supports bearing systems38in the turbine section28as well as setting airflow entering the low pressure turbine46.

In one disclosed embodiment, the gas turbine engine20includes a bypass ratio greater than about ten (10:1) and the fan diameter is significantly larger than an outer diameter of the low pressure compressor44. It should be understood, however, that the above parameters are only exemplary of one embodiment of a gas turbine engine including a geared architecture and that the present disclosure is applicable to other gas turbine engines.

An exploded view of a vane pack60is illustrated inFIG. 2. The vane pack60provides a gas path portion of the mid-turbine frame57in one example gas turbine engine. The vane pack may be provided in other sections of the engine20, such as the compressor section and other areas of the turbine section. In one example, the vane pack60is provided by multiple vane segments62circumferentially arranged and secured with respect to one another to provide an annular structure. Each vane62includes an inner and outer platform64,66joined to one another by the vane airfoil59.

In one example, the vanes62are constructed from a nickel alloy and brazed to one another. Forward inner and outer diameter rings68,70and aft inner and outer diameter rings72,74are secured to the vane segments62for structural reinforcement. In one example, the rings68,70,72,74are secured to the vane segments62by brazing.

Although multiple discrete circumferential vane segments are shown inFIG. 2, it should be understood that a cast and/or machined structure may provide clusters of vanes or all of the vanes and associated inner and outer platforms in a single, unitary annular configuration.

In one example, the vane airfoils59provide a hollow cavity76that accommodate oil lines, structural members, wires, bleed air conduits or other elements that may be passed from the outer portion of the engine static structure36to an inner portion.

Referring toFIGS. 2 and 3, the vanes62includes a boss78that receives a bushing79. A pin80is secured to the engine static structure36and received by the bushing79to locate the vane pack60with respect to the engine static structure36. Engine static structure36supports one of the bearings38mounted to the high pressure turbine shaft32.

First, second, third and fourth sealing rings82,84,86,88are supported by the engine static structure36and respectively engage the forward inner and outer diameter ring68,70and the aft inner and outer diameter ring72,74to seal the flow path gases within the core flow path C from other components.

As shown inFIGS. 3 and 4, the high pressure turbine section54includes an aft stage blade90, which includes a pocket94. The forward inner diameter ring68includes an end100secured around the vanes60that extends proud of an axial end of the vanes, in the example the leading edge99of the inner platform64. The end100provides an annular lip that is arranged at least partially within the pocket94and radially beneath the blade platform96. The forward inner diameter ring68is secured to the main segments62at an interface98by brazing, for example, if one or more of the vane segments62begins to separate from the forward inner diameter ring68, the vane segments62will not physically interfere with the rotation of the aft stage blade90.

The low pressure turbine section46includes a forward stage blade92. In the example, the aft inner diameter ring72does not extend beyond the vane segment62as does the forward inner diameter ring68, since there is more clearance between the vane segments62and the forward stage blade92. However, an end of the forward outer diameter ring70and aft inner and outer diameter rings72,74may extend axially beyond the vane segments62if desired where running clearances are tighter.

In the example shown inFIG. 5, the blade190includes a platform196having a lip received in an annular pocket194provided by the end200of the ring168, which is secured to the vane162. Thus, it should be understood that the platform and end may include any geometry suitable for providing a seal between the blade and vane.

Referring toFIG. 6, discrete single vanes or cluster of vanes is shown at290and is supported or hung relative to the engine static structure36by an attachment feature, such as a hook291. The vane segment262and ring268include complementary shaped interlocking features to prevent the ring268from migrating axially toward the blade. In the example, one of the interlocking features is a groove269and the other of the interlocking features is a tab271. In another example, the interlocking features may be provided by conical surfaces that provide a wedge-like interface. The interlocking features may obviate the need for any additional mechanical securing elements, such as brazing and/or fasteners.

Although example embodiments have been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that and other reasons, the following claims should be studied to determine their true scope and content.