BACKGROUND

A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section may include low and high pressure compressors, and the turbine section may also include low and high pressure turbines.

Airfoils in the turbine section are typically formed of a superalloy and may include thermal barrier coatings to extend temperature capability and lifetime. Ceramic matrix composite (“CMC”) materials are also being considered for airfoils. Among other attractive properties, CMCs have high temperature resistance. Despite this attribute, however, there are unique challenges to implementing CMCs in airfoils.

SUMMARY

A vane arc segment according to an example of the present disclosure includes an airfoil fairing that has first and second fairing platforms and a hollow airfoil section extending there between. A spar has a spar platform adjacent the first fairing platform and a hollow spar leg that extends from the spar platform and through the hollow airfoil section. The hollow spar leg has an internal passage for receiving cool air there through. The spar leg has a clevis mount that is distal from the spar platform and that protrudes from the second fairing platform. The clevis mount includes first and second prongs with aligned holes and a pin that extends through the aligned holes. A pin fairing extends over the pin between the first and second prongs for guiding the cooling air around the pin. A support platform is adjacent the second fairing platform. The support platform has a through-hole through which clevis mount extends. The pin locks the support platform to the spar leg such that the airfoil fairing is trapped between the spar platform and the support platform.

In a further embodiment of any of the foregoing embodiments, the pin fairing seals the pin from the internal passage.

In a further embodiment of any of the foregoing embodiments, the pin fairing is a cylindrical segment.

In a further embodiment of any of the foregoing embodiments, the pin fairing is planar.

In a further embodiment of any of the foregoing embodiments, the pin fairing includes a bearing surface in contact with the pin.

In a further embodiment of any of the foregoing embodiments, the bearing surface includes a hardcoat.

In a further embodiment of any of the foregoing embodiments, the pin fairing is welded to the first and second prongs.

In a further embodiment of any of the foregoing embodiments, the pin fairing has an apex that defines a throat of the internal passage. The internal passage changing at the apex from converging to diverging.

A spar according to an example of the present disclosure includes a spar platform and a hollow spar leg that extends from the spar platform. The hollow spar leg has an internal passage for receiving cooling air there through. A clevis mount that is distal from the spar platform includes first and second prongs with aligned holes for receiving a pin there through. A pin fairing extends over the aligned holes between the first and second prongs for guiding the cooling air.

In a further embodiment of any of the foregoing embodiments, the pin fairing is a cylindrical segment.

In a further embodiment of any of the foregoing embodiments, the pin fairing is planar.

In a further embodiment of any of the foregoing embodiments, the pin fairing includes a bearing surface.

In a further embodiment of any of the foregoing embodiments, the bearing surface includes a hardcoat.

In a further embodiment of any of the foregoing embodiments, the pin fairing is welded to the first and second prongs.

In a further embodiment of any of the foregoing embodiments, the pin fairing has an apex that defines a throat of the internal passage. The internal passage changing at the apex from converging to diverging.

A gas turbine engine according to an example of the present disclosure includes a compressor section, a combustor in fluid communication with the compressor section, and a turbine section in fluid communication with the combustor. The turbine section has vane arc segments disposed about a central axis of the gas turbine engine. Each of the vane arc segments includes an airfoil fairing having first and second fairing platforms and a hollow airfoil section that extends there between. A spar has a spar platform adjacent the first fairing platform and a hollow spar leg that extends from the spar platform and through the hollow airfoil section. The hollow spar leg has an internal passage for receiving cool air there through. A clevis mount that is distal from the spar platform and that protrudes from the second fairing platform includes first and second prongs with aligned holes and a pin extending through the aligned holes. A pin fairing extends over the pin between the first and second prongs for guiding the cooling air around the pin. A support platform adjacent the second fairing platform, has a through-hole through which clevis mount extends. The pin locks the support platform to the spar leg such that the airfoil fairing is trapped between the spar platform and the support platform.

In a further embodiment of any of the foregoing embodiments, the pin fairing has an apex that defines a throat of the internal passage. The internal passage changing at the apex from converging to diverging.

In a further embodiment of any of the foregoing embodiments, the pin fairing seals the pin from the internal passage.

In a further embodiment of any of the foregoing embodiments, the pin fairing includes a bearing surface in contact with the pin, and the bearing surface includes a hardcoat.

