Hydroformed balance shaft
AssigneeLinamar Corporation
InventorsMichael R. Biga, Allen W. Hale, Jan Krassler, Mario Lindner, Markus Haertel
Life of this patent
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Abstract
An engine balance shaft (20) for an internal combustion engine (24) is provided having reduced total mass and rotational inertia while having sufficient bending stiffness and sufficient unbalance mass. The balance shaft (20) is formed by fixedly coupling a counterweight (56), a front bearing journal (68), a rear bearing journal (60), a tail piece (40), and a nose piece (44) to a hollow tube (52). The hollow tube (52) is hydroformed to expand the diameter of the tube and fasten the desired components to the tube (52).
Claims26
An engine balance shaft for an internal combustion engine, said balance shaft comprising:
- a hollow tube having a first side wall extending between a first end and a second end of said tube and a tube passageway extending longitudinally through said tube between a first end opening and a second end opening;
- a front bearing journal having a first cylindrical wall with a first passageway extending between opposing ends of said first cylindrical wall, said first passageway configured such that at least a first portion of said tube passes through said first passageway;
- a rear bearing journal having a second cylindrical wall with a second passageway extending between opposing ends of said second cylindrical wall, said second passageway configured such that at least said first portion of said tube passes through said second passageway;
- an elongated counterweight configured to be fixedly coupled with said tube;
- wherein after said tube is assembled with said front bearing journal and said rear bearing journal by passing said first portion of said tube through said first and second passageways, and after said tube is assembled with said elongated counterweight, said tube is expanded through a hydroforming process to fixedly couple said front and rear bearing journals on said tube.
Dependencies are inferred from the claim text.