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

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 (D1) between the geometric center to the outer-race second annular face and a second distance (D2) between the geometric center to the inner-race second annular face, wherein D2 is greater than D1;
• 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.

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 annular face, and an inner-race faying surface connecting the first annular face to the second annular face, wherein the inner-race comprises of a high-strength steel,
• 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 of a gearbox,
• a rolling element disposed between the outer-race and the inner-race, wherein the rolling element includes a geometric center;
• a first distance (D1) between the geometric center to the outer-race second annular face and a second distance (D2) between the geometric center to the inner-race second annular face, wherein D2 is greater than D1;
• wherein the inner-race faying surface is in intimate contact with the external faying cylindrical shaft surface and the second annular face of the inner-race is coplanar with the distal end shaft surface;
• wherein the annular beveled shaft edge cooperates with the inner-race faying surface to define a half-V shaped annular groove;
• and
• a laser weld joint formed in the annular half-V shaped groove joining 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.