US 11,753,940 B2
Steam turbine rotor blade
Yasuhiro Sasao, Tokyo (JP); Soichiro Tabata, Tokyo (JP); Ryo Takata, Tokyo (JP); and Chongfei Duan, Tokyo (JP)
Assigned to MITSUBISHI HEAVY INDUSTRIES, LTD., Tokyo (JP)
Filed by MITSUBISHI HEAVY INDUSTRIES, LTD., Tokyo (JP)
Filed on Nov. 19, 2021, as Appl. No. 17/531,116.
Claims priority of application No. 2020-195363 (JP), filed on Nov. 25, 2020.
Prior Publication US 2022/0162947 A1, May 26, 2022
Int. Cl. F01D 5/14 (2006.01); F01D 5/22 (2006.01); F01D 25/32 (2006.01)
CPC F01D 5/141 (2013.01) [F05D 2220/31 (2013.01); F05D 2240/30 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A steam turbine rotor blade having, at an intermediate position in a blade length direction thereof, a tie boss for connection to an adjacent blade, wherein
the steam turbine rotor blade includes a leading edge side protrusion that extends in an embankment shape in a blade chord length direction at the intermediate position in the blade length direction,
a start end of the leading edge side protrusion is located on a suction side surface and a terminal end of the leading edge side protrusion is located on a pressure side surface, and
the leading edge side protrusion continues from the start end to the terminal end via a blade leading edge, and the leading edge side protrusion in the blade length direction overlaps with the tie boss as viewed from an upstream side of the steam turbine rotor blade,
wherein
the leading edge side protrusion extends such that a distance thereof from a blade root monotonically increases from the start end to the terminal end,
a cross sectional shape of the leading edge side protrusion is set to satisfy 2<W/D<100, wherein the D is a thickness of the leading edge side protrusion taken in a direction normal to a blade surface, the W is a width of the leading edge side protrusion taken in the blade length direction,
on a suction side of the rotor blade, the leading edge side protrusion is inclined to an outer side in a radial direction toward the leading edge of the rotor blade, and on a pressure side of the rotor blade, the leading edge side protrusion is inclined to the outer side in the radial direction toward a blade trailing edge.