High hardness steel race welded to a carburized steel shaft and a method of welding the same

Patent metadata

Field	Value
Publication number	US-12434332-B2
Application number	US-202318299223-A
Country	US
Kind code	B2
Filing date	Apr 12, 2023
Priority date	Apr 12, 2023
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

A gear box having a carburized shaft and steel bearing assembly. The bearing includes an inner-race and an outer-race. The shaft includes a distal end surface extending perpendicularly from a shaft faying surface and a shaft annular beveled edge. The shaft faying surface is in intimate contact with the inner-race. The inner-race second annular face is coplanar with the distal end surface. The shaft annular beveled edge cooperates with the inner-race faying surface to define a half-V shaped groove. An annular weld joint is formed in the half-V shaped groove thereby joining the shaft to the inner-race. The outer-race includes a first width (W 1 ) and the inner-race includes a second width (W 2 ). W 2 is wider than W 1 by greater than 0 millimeters (mm) to about 10 mm.

First claim

The invention claimed is:

1. A gear box for a vehicle, comprising:
a housing;
a rolling-element bearing comprising:
an inner-race having an inner-race first annular face, an inner-race second annular face opposite the inner-race first annular face, and an inner-race faying surface connecting the inner-race first annular face to the inner-race second annular face;
an outer-race having an outer-race first annular face, an outer-race second annular face opposite the outer-race first annular face, and an outer-race faying surface connecting the outer-race first annular face to the outer-race second annular face, wherein the outer-race is concentric with the inner-race and the outer-race faying surface is joined to the housing;
a rolling element disposed between the outer-race and the inner-race, wherein the rolling element includes a geometric center; and
a first distance (D 1 ) between the geometric center to the outer-race second annular face and a second distance (D 2 ) between the geometric center to the inner-race second annular face, wherein D 2 is greater than D 1 ; and

a shaft comprising a shaft faying surface, a distal end surface extending perpendicularly from the shaft faying surface, and a shaft angled surface extending from the shaft faying surface to the distal end surface to define a shaft annular beveled edge;
wherein the shaft faying surface is in contact with the inner-race faying surface, and the inner-race second annular face is coplanar with the distal end surface;
wherein the shaft annular beveled edge cooperates with the inner-race faying surface to define a half-V shaped groove; and
a laser weld joint formed in the half-V shaped groove to join the shaft to the inner-race;
wherein the inner-race is formed of a high hardness steel;
wherein the shaft is a carburized shaft; and
wherein an outer carburized layer of the shaft is removed to define the shaft annular beveled edge.

2. The gear box of claim 1 , wherein:
the outer-race first annular face is coplanar with the inner-race first annular face;
the outer-race includes a first width (W 1 ) and the inner-race includes a second width (W 2 ); and
W 2 is wider than W 1 by greater than 0 millimeters (mm) to about 10 mm.

3. The gear box of claim 1 ,
wherein D 2 is greater than D 1 by greater than 0 mm to 10 mm.

4. The gear box of claim 1 , wherein:
the inner-race includes an inner-race angled surface extending from the inner-race faying surface to the inner-race second annular face to define an inner-race annular beveled edge;
the shaft annular beveled edge cooperating with the inner-race annular beveled edge to define a V-shaped groove; and
the laser weld joint is formed in the V-shaped groove to join the shaft to the inner-race.

5. The gear box of claim 4 , wherein the V-shaped groove includes a depth of about 1 mm to about 5 mm.

6. The gear box of claim 5 , wherein the V-shaped groove includes a width of greater than 0 mm to about 3 mm.

7. The gear box of claim 4 , wherein the laser weld joint includes a plurality of uniformly circumferentially spaced weld segments formed in a predetermined sequence configured to minimize weld stress and potential distortion of the rolling-element bearing.

8. The gear box of claim 7 , wherein the laser weld joint comprises a welding alloy having greater than 10 weight percent of nickel.

9. The gear box of claim 8 , further comprising an electric motor having a rotor shaft operable to transfer torque to the shaft.

10. A method of welding a rolling-element bearing to a shaft comprising:
providing the shaft having an annular surface perpendicular to a rotational axis-A of the shaft, an external cylindrical surface extending from the annular surface in a direction parallel to the rotational axis-A, a distal end surface extending from the external cylindrical surface parallel to the annular surface, and an angled surface extending from the external cylindrical surface to the distal end surface to define a shaft annular beveled edge;
providing the rolling-element bearing having:

an inner-race including an external surface defining a first annular face, a second annular face opposite the annular first face, and an inner-race faying surface connecting the first annular face to the second annular face, and
an outer-race having an outer-race first annular face, an outer-race second annular face opposite the outer-race first annular face, and an outer-race faying surface connecting the outer-race first annular face to the outer-race second annular face, wherein the outer-race is concentric with the inner-race and the outer-race faying surface is joined to a housing; and
assembly the rolling-element bearing to the shaft such that the inner-race faying surface is in intimate contact with the external cylindrical surface of the shaft and the second annular face of the inner-race is coplanar with the distal end surface of the shaft;
wherein the shaft annular beveled edge cooperates with the inner-race faying surface to define an annular half-V shaped groove;
forming a laser weld joint in the annular half-V shaped groove to join the shaft to the inner-race;

wherein the rolling-element bearing further includes:
a rolling element disposed between the outer-race and the inner-race, wherein the rolling element includes a geometric center, and

a first distance (D 1 ) between the geometric center to the outer-race second annular face and a second distance (D 2 ) between the geometric center to the inner-race second annular face, wherein D 2 is greater than D 1 ;
wherein the inner-race is formed of a high hardness steel;
wherein the shaft is a carburized shaft; and removing an outer carburized layer of the shaft to define the shaft annular beveled edge prior to forming the laser weld joint.

11. The method of welding a rolling-element bearing to a shaft of claim 10 , wherein forming the laser weld joint in the annular half-V shaped groove includes fusing a welding alloy having greater than 10 percent by weight of nickel to the shaft and inner-race.

12. The method of welding a rolling-element bearing to a shaft of claim 11 , wherein:
the inner-race further comprises an inner-race angled surface extending from the inner-race faying surface to the inner-race second annular face to define an inner-race beveled edge;
wherein the inner-race beveled edge cooperates with the shaft annular beveled edge to define an annular V-shaped groove; and
wherein forming the laser weld joint includes forming the laser weld joint in the annular V-shaped groove.

13. The method of welding a rolling-element bearing to a shaft of claim 12 , wherein forming the weld laser joint in the annular V-shaped groove includes forming a plurality of equally spaced weld segments in a criss-crossing sequence configured to minimize weld stress and potential distortion of the rolling-element bearing.

14. A shaft-bearing assembly comprising:
a carburized steel shaft rotatable about an axis-A, wherein the shaft includes an external faying cylindrical shaft surface extending in a direction parallel to the axis-A, a distal end shaft surface extending from the external faying cylindrical shaft surface in a direction perpendicular to the axis-A, and a shaft angled surface extending from the external faying cylindrical surface to the distal end shaft surface to define an annular beveled shaft edge, wherein the annular beveled shaft edge is free of a carburized layer;
a rolling-element bearing comprising:

an inner-race having an external surface defining a first annular face, a second annular face opposite the first

Assignees

• Gm Global Tech Operations Llc

Inventors

• Li Huaxin
• Liu Yi
• Zhou Sen Jiang
• Gayney Jack M

Classifications

• B23K2101/008

  Gears · CPC title

• B23K31/003

  relating to controlling of welding distortion · CPC title

• B23K2101/005

  Camshafts · CPC title

• B23K26/242 Primary

  Fillet welding, i.e. involving a weld of substantially triangular cross section joining two parts · CPC title

• B23K31/02 Primary

  relating to soldering or welding · CPC title