Gas turbine bucket shanks with seal pins

1. A shank assembly, comprising:

a shank with a platform comprising a first slash face;

a seal pin slot extending into the first slash face, wherein an end of the seal pin slot is chamfered; and

a seal pin disposed in the seal pin slot, the seal pin comprising a dome-shaped end positioned adjacent to the end of the seal pin slot, wherein a ratio between a dome radius of the dome-shaped end of the seal pin to a pin radius of a central portion of the seal pin is greater than or equal to 1.1 and less than or equal to 1.8, wherein the central portion has a constant radius, wherein the dome-shaped end of the seal pin has a first portion and a second portion, wherein the first portion is adjacent to the central portion and comprises the constant radius, wherein the second portion is disposed opposite the first portion and comprises a radius less than the constant radius, wherein the end of the seal pin slot and the dome-shaped end of the seal pin collectively reduce a leakage area about the platform.

2. The shank assembly of claim 1 , wherein the shank further comprises a second slash face that is substantially planar.

3. The shank assembly of claim 1 , wherein the seal pin slot comprises a slot length and a depth.

4. The shank assembly of claim 3 , wherein the seal pin has a seal pin length less than the slot length.

5. The shank assembly of claim 1 , wherein the central portion is substantially cylindrical and is positioned adjacent to the dome-shaped end.

6. The shank assembly of claim 1 , wherein a slot width of the seal pin slot is greater than the constant radius, such that the slot pin can move within the seal pin slot.

7. A method of reducing leakage flow in turbine wheel space cavities, the method comprising:

providing a first near flow path seal shank with a first platform comprising a first slash face;

providing a second near flow path seal shank with a second platform comprising a second slash face, wherein the second slash face is substantially planar and positioned adjacent to the first slash face;

positioning a seal pin in a seal pin slot disposed within the first slash face, wherein the seal pin comprises a dome-shaped end positioned adjacent to an end of the seal pin slot, wherein the end of the seal pin slot is chamfered, and wherein a ratio between a dome radius of the dome-shaped end of the seal pin to a pin radius of a central portion of the seal pin is greater than or equal to 1.1 and less than or equal to 1.8, wherein the central portion has a constant radius, wherein the dome-shaped end of the seal pin has a first portion and a second portion, wherein the first portion is adjacent to the central portion and comprises the constant radius, wherein the second portion is disposed opposite the first portion and comprises a radius less than the constant radius, wherein the end of the seal pin slot and the dome-shaped end of the seal pin collectively reduce a leakage area about the platform; and

flowing cooling air in between the first slash face and the second slash face, wherein a hot gas path of the hot gas is occluded by the seal pin.

8. A gas turbine shank assembly, comprising:

a first shank comprising a first platform and a first dovetail extending from the first platform, the first platform comprising a first slash face on a first side of the first platform and a second slash face on a second side of the first platform opposite the first side;

a seal pin slot comprising a chamfered end and extending into the first slash face, the seal pin slot comprising a length defined along a major axis of the first slash face, a width defined along a minor axis of the first slash face, and a depth defined into the first slash face;

a seal pin disposed in the seal pin slot, the seal pin comprising a dome portion and a central portion disposed adjacent to the dome portion, wherein the central portion comprises a constant diameter, and the dome portion comprises a first end adjacent to the central portion and a second end forming an end of the seal pin, the first end having the constant diameter of the central portion, and the second end having a diameter less than the constant diameter, and wherein the chamfered end of the seal pin slot corresponds to the dome portion of the seal pin, such that the depth of the seal pin slot decreases across the first end of the seal pin slot, wherein a ratio between a dome radius of the dome portion to a pin radius of the central portion is greater than or equal to 1.1 and less than or equal to 1.8; and

a second shank positioned adjacent to the first shank comprising a second platform with a third slash face positioned such that the seal pin is retained in the seal pin slot,

wherein the chamfered end of the seal pin slot and the dome portion of the seal pin collectively reduce a leakage area about the first shank and the second shank.

9. The gas turbine shank assembly of claim 8 , further comprising a slash face gap between the first platform and the second platform, wherein the seal pin occludes a portion of the slash face gap.

10. The gas turbine shank assembly of claim 8 , wherein the third slash face is substantially planar.