Method for making an impeller from sector segments

Patent metadata

Field	Value
Publication number	US-2016003257-A1
Application number	US-201414769393-A
Country	US
Kind code	A1
Filing date	Feb 19, 2014
Priority date	Feb 20, 2013
Publication date	Jan 7, 2016
Grant date	—

Abstract

A manufacturing technique for impellers for a centrifugal rotating machine is provided. The impeller is made by composition of single vanes pieces that fit to the hub or directly to the rotor shaft by welding, friction welding or a mechanical locking system. The manufacturability of the segments is easy fast and cheap and make it possible to use advanced manufacturing technologies like additive manufacturing of the type of Direct Metal Laser Melting.

First claim

What is claimed is:

1 . A method for manufacturing an impeller for a centrifugal rotating machine comprising a substantially disk shaped main body comprising a front surface and a rear surfaces, a shroud comprising a front surface and a rear surfaces arranged spaced from the front surface of the main body, a plurality of blades, attached to the front surface of the main body joining the main body with the shroud wherein side surfaces of the blades, the front surface of the body, and the rear surface of the shroud form flow passages for compressing air, the method comprising
making a single segments of the impeller comprising a single blade, a section of the main body and the corresponding section of the shroud; and successively joining together the plurality of segments to form the impeller.

2 . The method according to claim 1 , wherein the segments are joined together by welding, or friction welding.

3 . The method according to claim 1 , wherein the impeller is attached to a hub that is attached to a rotor shaft of the machine, or is attached directly to the rotor shaft.

4 . The method according to claim 3 , wherein the impeller is attached to the hub or directly to the rotor shaft by Cold Metal Transfer (CMT) deposition.

5 . The method according to claim 1 , wherein the single segments are attached to the hub or directly to the rotor shaft of the machine.

6 . The method according to claim 3 , wherein the segments are attached to the hub or to the rotor shaft by welding, friction welding, or by a mechanical locking system.

7 . The method according to claim 6 , wherein the mechanical locking system comprises dovetail joints.

8 . The method according to claim 3 , wherein the impeller is fixed to the hub or to the rotor shaft by dovetail joints.

9 . The method according to claim 1 , wherein the segments are fastened together by a ring positioned in a groove formed on the rear surface of the main body.

10 . The method according to claim 1 , wherein the single segments are produced by direct metal laser melting.

11 . An impeller for a centrifugal rotating machine the impeller comprising:
a substantially disk shaped main body comprising a front surface and a rear surfaces; a shroud having a front and a rear surfaces arranged spaced from the front surface of the main body; and a plurality of blades attached to the front surface of the main body joining the main body with the shroud, the side surfaces of the blades, the front surface of the body and the rear surface of the shroud forming flow passages for compressing air, wherein the impeller is composed by single segments comprising a single blade, a section of the main body and the corresponding section of the shroud, the single segments being joined together or fixed to the hub or directly to the rotor shaft.

12 . An impeller according to claim 11 , wherein the single segments have a dovetail key with inclined side surfaces on the side facing the external surface of the hub.

13 . An impeller according to claim 12 , wherein the hub present on its external surface dovetail grooves with inclined surfaces in mating relationship with the dovetail keys of the segments.

14 . An impeller according to claim 11 , wherein the hub present on its external surface dovetail grooves with inclined surfaces in mating relationship with the dovetail keys of the segments.

15 . The method according to claim 2 , wherein the impeller is attached to a hub that is attached to a rotor shaft of the machine, or is attached directly to the rotor shaft.

16 . A centrifugal compressor comprising:
an impeller comprising: a substantially disk shaped main body comprising a front surface and a rear surfaces; a shroud having a front and a rear surfaces arranged spaced from the front surface of the main body; and a plurality of blades attached to the front surface of the main body joining the main body with the shroud, the side surfaces of the blades, the front surface of the body and the rear surface of the shroud forming flow passages for compressing air, wherein the impeller is composed by single segments comprising a single blade , a section of the main body and the corresponding section of the shroud, the single segments being joined together or fixed to the hub or directly to the rotor shaft.

17 . A centrifugal compressor according to claim 16 , wherein the single segments have a dovetail key with inclined side surfaces on the side facing the external surface of the hub.

18 . A centrifugal compressor according to claim 16 , wherein the hub present on its external surface dovetail grooves with inclined surfaces in mating relationship with the dovetail keys of the segments.

Assignees

• Nuovo Pignone Srl

Inventors

• Palomba Sergio
• Lorenzi Lorenzo
• Bianchi Lorenzo

Classifications

• B23K20/12 Primary

  the heat being generated by friction; Friction welding · CPC title

• F04D29/624

  especially adapted for elastic fluid pumps · CPC title

• F04D29/284 Primary

  for compressors · CPC title

• F04D17/10

  for compressing or evacuating · CPC title

• F01D5/34

  Rotor-blade aggregates of unitary construction {, e.g. formed of sheet laminae; (discs formed of sheet laminae F01D5/028; ceramic materials F01D5/284, composite materials F01D5/282)} · CPC title