Method and apparatus for laser gear hardening
AssigneeThe Garrett Corporation
InventorsGary F. Benedict, Jim Eskildsen
Life of this patent
Estimating the term…
Abstract
Apparatus and method for laser hardening flank and root areas of gears are disclosed which utilize a non-linear scanning technique to produce a laser light bar which may be traversed over the flank and root areas of the gear to produce uniform case depth while preventing back-tempering by directing coolant flow on to gear tooth flanks opposite those currently being hardened.
Claims28
A method of hardening the flank of a first gear tooth, the flank of a second gear tooth, and the root area between said first and second gear tooth, comprising:
- supplying a high power laser light beam;
- focusing said high power laser light beam at a predetermined focal length on the gear to establish a focused laser light beam;
- scanning said focused laser light beam across the width of said gear to create a laser light bar;
- rotating said gear about its axis to traverse said laser light bar down said flank of said first gear tooth, across said root area between said first and second tooth, and up said flank of said second tooth;
- simultaneously moving said gear in a first direction to maintain as close as possible an approximation to perpendicularlity between said focused laser light beam and the surface of said gear on which said laser light bar is directed;
- and
- simultaneously moving said gear in a second direction orthogonal to said first direction to maintain said predetermined focal length.
A method of hardening a flank-root-flank area of a gear, comprising:
- scanning a focused, high power laser light beam across the surface of said gear in a direction parallel to the axis of said gear to produce a laser light bar having a predetermined focal length;
- traversing said flank-root-flank area of said gear with said laser light bar;
- maintaining the surface of said gear on which said laser light bar is directed in as close as possible to an orthogonal direction to said high power laser light beam while said flank-root-flank area of said gear is traversed;
- and
- maintaining said predetermined focal distance while said flank-root-flank area is traversed.
A method of hardening a V-shaped area of a gear including the flank of a first gear tooth, the flank of an adjacent gear tooth, and the root area between said first and second gear teeth, comprising:
- supplying a high power focused laser light beam having a predetermined focal length;
- scanning at a nonlinear rate the width of said V-shaped area with said high power focused laser light beam to produce a narrow bar-shaped uniform heating pattern across the width of said V-shaped area;
- traversing at a nonlinear rate said V-shaped area with the scanned high power focused laser light beam to produce the desired hardening characteristics throughout said V-shaped area.
A device for producing uniform case depth hardness in a flank-root-flank area of a gear utilizing a high power laser light beam, comprising:
- a focusing lens for establishing a predetermined focal length between the source of said high power laser light beam and the area of said gear on which said high power laser light beam is directed;
- a scanning mirror in the path of said high power laser light beam for establishing a bar-shaped laser light pattern on said gear in a direction parallel to the axis of said gear;
- means for traversing said flank-root-flank area of said gear with said bar-shaped laser light pattern to harden said flank-root-flank area of said gear.
A device for hardening a V-shaped area of a gear including the flank of a first gear tooth, the flank of a second gear tooth, and the root area between said first and second gear teeth, comprising:
- a high power laser light source;
- means for focusing laser light from said high power laser light source into a collimated laser light beam having a preset focal length;
- means for scanning said laser light beam onto said gear to produce a laser light bar across the width of said gear;
- means for traversing said V-shaped area with said laser light beam to produce a hardened surface in said V-shaped area, said traversing means maintaining said preset focal length and keeping the portion of said V-shaped area on which said laser light bar is directed approximately orthogonal to said scanned laser light beam.
Dependencies are inferred from the claim text.