Blade assembly with damping elements

• US 6,450,769 B2
• Filed: 03/08/2001
• Issued: 09/17/2002
• Est. Priority Date: 03/22/2000
• Status: Expired due to Fees

• Current Assignee: Alstom Technology Ltd. (Alstom SA)
• Original Assignee: Alstom Limited (Alstom SA)
• Inventors: Szwedowicz, Jaroslaw
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): NGUYEN, NINH H
• Application Number:
  US09/800,777
• Publication Number:
  US 20010024614A1
• Time in Patent Office: 558 Days
• Field of Search: 415/119, 416/239, 416/500, 416/190, 416/193.A
• US Class Current: 416/190
• CPC Class Codes: F01D 25/06 for preventing blade vibration means on blade-carrying members or blades F01D5/00
• CPC Class Codes: F01D 5/22 Blade-to-blade connections, e.g. for damping vibrations
• CPC Class Codes: F05D 2250/70 Shape
• CPC Class Codes: Y10S 416/50 Vibration damping features

Abstract

The present invention relates to a blade assembly with damping elements, which comprises a rotor (5) and blades (6) which are installed on the circumference of the rotor and have a blade platform (7), shank (14) and root (8). A damping element (9) is arranged between respectively adjacent blades (6), said damping element (9) being frictionally connected on rotation of the rotor (5), to at least a first region (1, 2) of a first of the respectively adjacent blades (6), and to a second region (3) of a second of the respectively adjacent blades (6). The blade assembly is characterized by the fact that the damping element (9) is configured and arranged between the first and second blades in such a way that the first region (1, 2) and the second region (3) are located at positions which are significantly spaced apart from one another in the radial direction.

This blade assembly provides efficient oscillation damping even in the case of small relative movements between adjacent blades.

Claims

1. A blade assembly comprising:

a rotor and a plurality of blades which are installed on the circumference of the rotor, said blades extending in a radial direction and each having a blade platform, a shank and a root; and

at least one damping element, said at least one damping element being arranged between respectively adjacent blades, and being frictionally connected during rotation of the rotor to at least a first region of a first of the respectively adjacent blades and a second region of a second of the respectively adjacent blades, wherein the first region is located in the upper third of a region of the first blade which extends from the blade platform to the rotor, and the second region is located in the lower third of a region of the second blade which extends from the blade platform to the rotor.

2. The blade assembly according to claim 1, wherein the first region is located on an underside of the blade platform of the first blade, and the second region is located on the shank of the second blade.

3. The blade assembly according to claim 1, wherein the first region is located on the shank near to the blade platform of the first blade, and the second region is located on the shank of the second blade.

4. The blade assembly according to claim 1, wherein the first region is located on an underside of the blade platform of the first blade, and the second region is located on the shank of the second blade, and

said at least one damping element being configured in such a way that, on rotation of the rotor, it is additionally frictionally connected to a third region on the blade platform of the second blade, which region is located opposite the first region.

5. The blade assembly according to claim 4, wherein a radial cross section of said at least one damping element has an elongate shape with a widened end region and with an asymmetry with respect to a longitudinal axis of said at least one damping element, the widened end region being wider than the distance between the adjacent blade platforms.

6. The blade assembly according to claim 1, wherein a radial cross section of said at least one damping element has an elongate shape whose length is greater than the distance between adjacent shanks of the respectively adjacent blades.

7. The blade assembly according to claim 1, wherein a radial cross section of said at least one damping element has a bent shape and said at least one damping element has opposite end regions such that during rotation of the rotor, one end region of said at least one damping element is in frictionally locking contact with an underside of the blade platform of the first blade, and the opposite end region of said at least one damping element is in frictionally locking contact with an underside of a projection formed on the shank of the second blade.

8. The blade assembly according to claim 1, wherein said at least one damping element is asymmetrically configured in such a way that its center of gravity is located close to at least one of the first region and the second region.

9. The blade assembly according to claim 1, wherein contact faces between said at least one damping element and at least one of the first region and the second region are embodied as planar faces.

10. The blade assembly according to claim 1, wherein said at least one damping element is prevented from moving perpendicularly with respect to the radial direction by guide grooves formed on at least one of the first region and the second region.