Patent ID: 9316105
Filing Date: 2016-04-19
CPC Classification: F01D,F05D

Claim Text:
1. A blade for a rotor of a turbine comprising: an airfoil; a shroud disposed at an outer end of the airfoil; and a platform disposed at an inner end of the airfoil, the platform including a top plate disposed adjacent to the airfoil, a shank disposed below the top plate and a fixing part disposed below the shank, the shank and the fixing part each extending in a radial direction of the blade, the shank including a front side and a back side opposite the front side and facing in a circumferential direction of the blade, as well as a downstream side and an upstream side opposite the downstream side and facing in an axial direction of the blade; an upstream wall projecting in the circumferential direction away from the shank and extending from the top plate toward the fixing part, the upstream wall at least partially covering the upstream side of the shank; a downstream wall projecting in the circumferential direction away from the shank and extending from the top plate toward the fixing part, the downstream wall at least partially covering the downstream side of the shank; at least one recess disposed in a region of the shank in at least one of the upstream wall and the downstream wall and at least partially penetrating the at least one of the upstream wall and the downstream wall in the axial direction, the at least one recess having an open side facing in a same direction as a respective one of the at least one of the upstream wall and the downstream wall, in which the at least one recess is disposed, is projecting; wherein the front side of the shank has a concave shape and the back side of the shank has a convex shape such that a circle tangenting the concave-shaped front side and the convex-shaped back side has a diameter C, wherein the at least one of the recesses has a width B in the radial direction at a corresponding outer end and a length A along the axial direction, the length A corresponding to a thickness of a corresponding section of the at least one of the upstream wall and the downstream wall and wherein the at least one recess has a depth D in the circumferential direction that increases or decreases along the axial direction and a depth difference E corresponding to a difference between a maximum depth Dmax and a minimum depth Dmin such that at least one of: the length A of the recess is less than (1.5×C); the width B of the recess is less than (0.7×C); and the depth difference E is less than (0.45×C); and wherein the airfoil has a length in the radial direction of between 100 mm and 772 mm.