Patent ID: 11890668
Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Field: Materials, metallurgy (Chemistry)
Classification: CPC B  F  Y | IPC B

Claim 0:
1. A method of manufacturing a cast steel alloy crankshaft for an internal combustion engine, the method comprising:
providing a negative sand cast mold of the crankshaft, the negative sand cast mold having cavities to form the crankshaft, the crankshaft comprising:
at least four main journals aligned on a crankshaft axis of rotation defining a centerline; and
at least three pin journals, each pin journal being disposed about a respective pin journal axis and positioned between the main journals, each of the respective pin journal axes being oriented parallel to and spaced radially from the crankshaft axis, each of the pin journals being joined to a pair of crank arms for force transmission between the pin journal and the pair of crank arms, each pair of crank arms being joined to a respective main journal for transmitting torque between the pair of crank arms and the main journal, each crank arm having a counterweight disposed opposite a respective pin journal relative to the centerline for balance and stability;

melting a first metallic material at a predetermined temperature to define a molten metallic material;
feeding the molten metallic material at a general riser connection angle of between 30° and 75° in the cavities of the negative sand cast mold;
cooling the molten metallic material at a predetermined solidification time in the negative sand cast mold to define a solidified metallic material having dimensions of the cast steel alloy crankshaft, wherein the predetermined solidification time is between 5 sec and 20 sec; and
separating the solidified metallic material from the negative sand cast mold to define the cast steel alloy crankshaft.