Net forged spiral bevel gear
AssigneeAmerican Axle & Manufacturing, Inc.
InventorsCurt MOEHLAU, Mohsen KOLIVAND, Dale K. BENEDICT
Life of this patent
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Abstract
A process for forming a finished spiral bevel gear includes forging a blank to form a forging having near net-shaped spiral bevel teeth, machining the forging, coining the forging to form a coined spiral bevel gear with net-shaped spiral bevel gear teeth; heat treating the coined spiral bevel and finishing the heat treated, coined spiral bevel gear without machining the net-shaped spiral bevel gear teeth in a machining operation that forms chips.
Claims15
A process for providing a spiral bevel gear and a spiral bevel pinion gear, the process comprising:
- providing a blank;
- heating the blank to a temperature in excess of a predetermined temperature threshold;
- forging the heated blank while the heated blank is at a temperature in excess of the predetermined temperature threshold to produce a forging, the forging having a first side and a second side, the first side comprising a plurality of near net-shaped spiral bevel gear teeth, the forging being formed of metal;
- machining the second side of the forging to a predetermined distance from a portion of the near net-shaped spiral bevel gear teeth to form a machined forging;
- without machining the near net-shaped spiral bevel gear teeth, forming a coined gear by cold working the machined forging in a coining die to induce plastic flow in the near net-shaped spiral bevel gear teeth and form net-shaped spiral bevel gear teeth that conform to a desired tooth profile with a desired degree of accuracy, wherein each of the net-shaped spiral bevel gear teeth has a pair of flanks, and wherein the desired tooth profile includes a contour of the flanks of the net-shaped spiral bevel gear teeth;
- heat-treating the coined gear to form a heat-treated gear;
- providing a spiral bevel pinion gear;
- and
- finishing the heat-treated gear without machining the net-shaped spiral bevel gear teeth in a chip forming operation to produce a finished spiral bevel gear;
- wherein the teeth of the finished spiral bevel gear that have a quality level in which the finished gear and the spiral bevel pinion gear, when meshed together, perform at or below a 50 micro-radian level of first harmonic transmission error when positioned in a predetermined spatial relationship.
A process for providing a spiral bevel gear and a spiral bevel pinion gear, the process comprising:
- providing a blank;
- heating the blank to a temperature that is greater than or equal to a predetermined forging temperature;
- forging the heated blank to form a forged gear having near net-shaped spiral bevel gear teeth;
- machining the forged gear to a predetermined thickness while locating off of the near net-shaped spiral bevel gear teeth to form a green machined forged gear;
- rotationally and axially engaging a coining die to the near net-shaped spiral bevel gear teeth of the green machined forged gear to induce plastic flow in the near net-shaped spiral bevel gear teeth to form an intermediate gear having net-shaped spiral bevel gear teeth that conform to a predetermined tooth form;
- heat-treating the intermediate gear to form a hardened intermediate gear;
- and
- lapping the net-shaped spiral bevel gear teeth of the hardened intermediate gear with a spiral bevel pinion gear to form a finished spiral bevel gear;
- wherein the net-shaped spiral bevel gear teeth are not machined in a chip-producing machining operation before the net-shaped spiral bevel gear teeth are lapped;
- and
- wherein the teeth of the finished spiral bevel gear have a quality level in which the finished gear and the spiral bevel pinion gear, when meshed together, perform at or below a 50 micro-radian level of first harmonic transmission error when positioned in a predetermined spatial relationship.
Dependencies are inferred from the claim text.