Turbine blade and diaphragm construction
AssigneeALSTOM Technology Ltd
InventorsDavid Paul Blatchford, David John Nelmes, Bryan Vincent Coltar
Life of this patent
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Abstract
An axial flow turbine blade and diaphragm construction comprises an annulus of static turbine blades 20 and inner and outer spacer rings 40, 42 having apertures 41, 43 shaped to accommodate inner and outer platform portions 22, 23 of the blades, whereby the platform portions and the spacer rings together form inner and outer port walls of the turbine diaphragm. A particular feature of the blades is that the inner and outer platform portions 22 and 23 have straight side edges 22B, 22C and 23B, 23C, which are joined to each other by curved leading edges 22D and 23D that in plan view have a shape that follows the edge of the corner fillet 24 in the region of the leading edge 26 of the aerofoil 21.
Claims18
A static blade for an axial flow turbine comprising:
- a) an aerofoil portion having a leading edge, a trailing edge, a pressure side, a suction side, and a chord line;
- b) radially inner and outer platform portions integral with the aerofoil portion;
- c) a corner fillet where the aerofoil portion meets each platform portion to form a smooth transition between the aerofoil portion and each platform portion;
- d) the platform portions in plan view comprising:
- i) a trailing edge formed to extend circumferentially of the turbine axis,
- ii) a straight side edge on each of the pressure side and the suction side of the aerofoil,
- iii) a curved leading edge that joins the side edges to each other and that in plan view has a shape that follows the edge of the corner fillet in the region of the leading edge of the aerofoil portion.
An axial flow turbine diaphragm construction comprising:
- a) an annulus of static turbine blades having an aerofoil portion with integral inner and outer platform portions, and
- b) inner and outer spacer rings having apertures therein shaped to accommodate the inner and outer platform portions respectively, whereby the platform portions and the spacer rings together form inner and outer port walls of the turbine diaphragm,
- wherein the turbine blades each have a corner fillet where the aerofoil portion meets each platform portion to form a smooth transition between the aerofoil portion and each platform portion, each platform portion comprising:
- i) a trailing edge formed to extend circumferentially of the turbine axis,
- ii) a straight side edge on each of the pressure side and the suction side of the aerofoil,
- iii) a curved leading edge that joins the side edges to each other and that in plan view has a shape that follows the edge of the corner fillet in the region of the leading edge of the aerofoil portion.
Dependencies are inferred from the claim text.