Rotor blade for a first phase of a gas turbine

• US 20060059890A1
• Filed: 09/15/2005
• Published: 03/23/2006
• Est. Priority Date: 09/21/2004
• Status: Active Grant

• Current Assignee: Nuovo Pignone SPA (Baker Hughes Company)
• Original Assignee: Nuovo Pignone SPA (Baker Hughes Company)
• Inventors: Sassanelli, Giuseppe, Boncinelli, Marco
• Granted Patent: US 7,530,794 B2
• Time in Patent Office: Days
• US Class Current: 60/230
• CPC Class Codes: F01D 5/141 Shape, i.e. outer, aerodynamic form F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147
• CPC Class Codes: F05D 2220/3212 the first stage of a turbine
• CPC Class Codes: F05D 2250/74 given by a set or table of xyz-coordinates
• CPC Class Codes: Y10S 416/02 Formulas of curves

Abstract

Blade (1) of a rotor for a first phase of a gas turbine having a profile identified by means of a series of closed intersection curves (20) between the profile itself and planes (X,Y) lying at distances (Z) from the central axis, each closed curve (20) has a first rounded end (21) and a second rounded end (22), which connect the trace of the first surface (3) with the trace of the second surface (5) in depression, the first end (21) first meets a gas flow of the turbine, each closed curve (20) has an axial chord (40) defined as the maximum distance of the first end (21) from the second end (22) along the axis (X), each closed curve (20) has a thickness (30) of the first end (21) defined as the maximum diameter of the circle inscribed in the first end (21); said dimensionless thickness (30), i.e. divided by the axial chord (40), has a quadric distribution according to a curve of the fourth order along the axis (Z).

Claims

1. A blade (1) of a rotor for a first phase of a gas turbine having a profile identified by means of a series of closed intersection curves (20) between the profile itself and planes (X,Y) lying at distances (Z) from the central axis, each closed curve (20) has a first rounded end (21) and a second rounded end (22) which connect the trace of the first surface (3) with the trace of the second surface (5) in depression, said first end (21) first meets a gas flow of the turbine, each closed curve (20) has an axial chord (40) defined as the maximum distance of the first end (21) from the second end (22) along the axis (X), each closed curve (20) has a thickness (30) of said first end (21) defined as the maximum diameter of the circle inscribed in the first end (21), characterized in that said dimensionless thickness (30), i.e. divided by the axial chord (40), has a quadric distribution according to a curve of the fourth order along the axis (Z).

2. The blade (1) according to claim 1, characterized in that said closed curves (20) are defined according to Table I, whose values refer to a room temperature profile and for each closed curve (20) are divided by value, expressed in millimetres, of the respective axial chord (40).

3. The blade (1) according to claim 1 or 2, characterized in that the profile of each blade (1) has a tolerance of +/−

0.3 mm in a normal direction with the profile of the blade (1) itself.

4. The blade (1) according to any of the claims from 1 to 3, characterized in that the profile of each blade (1) comprises an anti-wear coating.

5. The blade (1) according to claim 4, characterized in that said coating has a thickness ranging from 0 to 0.5 mm.

6. A rotor for a first phase of a turbine comprising a series of blades according to any of the claims from 1 to 5.

7. A rotor blade for a first phase of a gas turbine as previously described and illustrated and for the purposes specified above.