Patent ID: 11959394
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 8:
9. The turbine rotor blade according to claim 8,
wherein, the upstream intermediate fillet portion has a second cross section demarcated by:
a second curved line connecting the suction surface and the upper surface of the platform portion, the second curved line being defined by a part of an ellipse;
a third line segment extending from a position where the second curved line is connected to the suction surface to the upper surface of the platform portion along a blade height direction; and
a fourth line segment extending from a position where the third line segment is connected to the upper surface of the platform portion to a position where the second curved line is connected to the upper surface,

wherein the downstream intermediate fillet portion has a third cross section demarcated by:
a third curved line connecting the suction surface and the upper surface of the platform portion, the third curved line being defined by a part of an ellipse;
a fifth line segment extending from a position where the third curved line is connected to the suction surface to the upper surface of the platform portion along a blade height direction; and
a sixth line segment extending from a position where the fifth line segment is connected to the upper surface of the platform portion to a position where the third curved line is connected to the upper surface,

wherein a curvature radius of the ellipse defining the second curved line in the upstream intermediate fillet portion is larger than a curvature radius of the ellipse defining the first curved line in the central fillet portion, when compared at a same blade-height-directional position, and
wherein a curvature radius of the ellipse defining the third curved line in the downstream intermediate fillet portion is larger than the curvature radius of the ellipse defining the first curved line in the central fillet portion, when compared at the same blade-height-directional position.