Deep rolling tool for blade fatigue life enhancement

Patent metadata

Field	Value
Publication number	US-9573175-B2
Application number	US-201414567522-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 18, 2013
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A device and methods are provided for deep rolling. In one embodiment, a deep rolling tool for applying compressive stress with rolling elements includes a fork having a base section and a plurality of fork arms, each fork arm extends outwardly from the base section and the fork arms are separated from one another to form an opening. The deep rolling tool may also include rolling elements, wherein each rolling element is mounted at the distal end of a fork arm, and the rolling elements are configured to apply a compressive stress to articles received by the deep rolling tool.

First claim

What is claimed is:

1. A deep rolling tool for applying compressive stress, the deep rolling tool comprising:
a flexible first fork arm and a flexible second fork arm each extending outwardly from a base section, wherein the flexible first fork arm and the flexible second fork arm are separated from one another to form an opening;
a first rolling element rotatably secured to a distal end of the flexible first fork arm;
a second rolling element rotatably secured to a distal end of the flexible second fork arm;
wherein the flexible first fork arm and the flexible second fork arm are configured to locate the first rolling element and the second rolling element in a facing spaced relationship with respect to each other and wherein the flexible first fork arm and wherein the flexible second fork arm extend outwardly from the base section without a pivot such that movement of the distal end of the flexible first fork arm with respect to the distal end of the flexible second fork arm is dependent upon a flexural stiffness of the flexible first fork arm and a flexural stiffness of the flexible second fork arm; and
wherein the first rolling element and the second rolling element are configured to apply a compressive stress to an article received in the opening.

2. The deep rolling tool of claim 1 , wherein the first rolling element and the second rolling element each have a crowned roller, the crowned roller having a minor radius for contacting the article received by the rolling tool, and a major diameter adapted to provide a load capacity.

3. The deep rolling tool of claim 1 , wherein the deep rolling tool is configured to apply residual stress to the article and the article is at least one of a turbine blade, a compressor blade, a fan blade, a bladed disk, a bladed element and a metal object.

4. The deep rolling tool of claim 1 , wherein the compressive stress improves at least one of a fatigue life of the article, a surface finish of the article and an aerodynamic performance of the article.

5. The deep rolling tool of claim 1 , wherein the first rolling element and the second rolling element apply a residual stress that inhibits crack propagation in the article.

6. The deep rolling tool of claim 1 , wherein the first rolling element and the second rolling element are secured to the deep rolling tool with roller bushings.

7. The deep rolling tool of claim 1 , wherein the first rolling element and the second rolling element each rotate about a center axis and wherein the center axis of the first rolling element is parallel to the center axis of the second rolling element.

8. The deep rolling tool of claim 1 , wherein the article is a bladed object.

9. A deep rolling tool for applying compressive stress with rolling elements, the deep rolling tool comprising:
a flexible first fork arm and a flexible second fork arm each extending outwardly from a base section wherein the flexible first fork arm and the flexible second fork arm are separated from one another to form an opening;
a first crowned rolling element rotatably secured to a distal end of the flexible first fork arm;
a second crowned rolling element rotatably secured to a distal end of the flexible second fork arm;
wherein the flexible first fork arm and the flexible second fork arm are configured to locate the first crowned rolling element and the second crowned rolling element in a facing spaced relationship with respect to each other and wherein the flexible first fork arm and the flexible second fork arm extend outwardly from the base section without a pivot such that movement of the distal end of the flexible first fork arm with respect to the distal end of the flexible second fork arm is dependent upon a flexural stiffness of the flexible first fork arm and a flexural stiffness of the flexible second fork arm; and
wherein the first crowned rolling element and the second crown rolling element are configured to apply a compressive stress to an article located between the first crowned rolling element and the second crowned rolling element.

10. The deep rolling tool of claim 9 , wherein the first crowned rolling element and the second crowned rolling element each have a major diameter adapted to provide a load capacity.

11. The deep rolling tool of claim 9 , wherein the deep rolling tool is configured to apply residual stress to the article and the article is at least one of a turbine blade, a compressor blade, a fan blade, a bladed disk, a bladed element and a metal object.

12. The deep rolling tool of claim 9 , wherein the compressive stress improves at least one of a fatigue life of the article, a surface finish of the article and an aerodynamic performance of the article.

13. The deep rolling tool of claim 9 , wherein the first crowned rolling element and the second crowned rolling element are adapted to apply a residual stress that inhibits crack propagation in the article.

14. The deep rolling tool of claim 9 , wherein the first crowned rolling element and the second crowned rolling element are secured to the deep rolling tool with roller bushings.

15. The deep rolling tool of claim 9 , wherein the first crowned rolling element and the second crowned rolling element rotate about a center axis wherein the center axis of the first crowned rolling element is parallel to the center axis of the second crowned rolling element.

16. The deep rolling tool of claim 9 , wherein the article is a bladed object.

Assignees

• United Technologies Corp

Inventors

• Hawkes Justin R
• Gray Eric
• Kountanya Raja
• Zadrozny Gary Paul
• Liou Joe J

Classifications

• C21D7/08

  by burnishing or the like · CPC title

• B23P9/02

  Treating or finishing by applying pressure, e.g. knurling (B23P9/04 takes precedence) · CPC title

• B24B39/003 Primary

  the working tool being composed of a plurality of working rolls or balls · CPC title

• B21B27/02 Primary

  Shape or construction of rolls (for rolling metal of indefinite length in repetitive shapes specially designed for the manufacture of particular objects B21H8/02 {; B21B27/005 takes precedence}) · CPC title

• B21B31/02

  Rolling stand frames {or housings}; Roll mountings {; Roll chocks} · CPC title