Balance shafts having minimal mass
AssigneeSimpson Industries, Inc.
InventorsDavid L. Killion, Michael D. Hendrian, Robert J. Crist
Life of this patent
Estimating the term…
Abstract
A balance shaft for rotating machinery such as a vehicle engine which minimizes the mass or weight of the balance shaft by optimizing the material usage in accordance with the standards and parameters established for the balance shaft. For rotating couple-type shafts, the two balance weights each have surfaces substantially forming hyperbolic curves. In addition, the connector portion between the balance weights has a cross-section with recessed sides in order to reduce the mass or weight of the balance shaft. For single unbalance-type shafts, the connector portion also has a cross-section with recessed sides.
Claims37
A balance shaft comprising:
- a body member having a longitudinal axis, a first end and a second end;
- a first bearing surface adjacent said first end and a second bearing surface adjacent said second end;
- a first balance weight adjacent said first end and a second balance weight adjacent said second end;
- and
- a connector portion on said body member between said first and second balance weights;
- said first and second balance weights positioned on opposite sides of said longitudinal axis and providing a rotating couple when said balance shaft is rotated around said longitudinal axis;
- said first balance weight having a first elongated surface thereon extending in the direction of said longitudinal axis and said second balance weight having a second elongated surface thereon extending in the direction of said longitudinal axis;
- said first and second elongated surfaces being shaped substantially as hyperbolic curves substantially along the length of said surfaces;
- wherein the masses of the first and second balance weights are minimized.
A balance shaft comprising:
- a body member having a longitudinal axis, a first end and a second end;
- a first bearing surface adjacent said first end and a second bearing surface adjacent said second end;
- a first balance weight adjacent said first end and a second balance weight adjacent said second end;
- and
- a connector portion on said body member between said first and second balance weights;
- said first and second balance weights positioned on opposite sides of said longitudinal axis and providing a rotary couple when said balance shaft is rotated around said longitudinal axis;
- said connector portion having at least one elongated recess therein, said recess being elongated in the direction of said longitudinal axis;
- wherein the mass of the balance shaft is minimized.
A method of optimizing the mass of a rotating couple-type balance shaft for a vehicle engine, said balance shaft having a pair of bearing surfaces adjacent the ends thereof, a pair of opposed balance weights adjacent the ends thereof, a connector portion between said balance weights, and a longitudinal axis, and said balance weights each having an elongated surface thereon extending in the direction of said longitudinal axis, said method comprising the step of forming the shapes of the elongated surfaces on said balance weights substantially as hyperbolic curves substantially along the lengths of said surfaces.
A method of optimizing the mass of a rotating couple-type balance shaft for a vehicle engine, said balance shaft having a pair of bearing surfaces adjacent the ends thereof, a pair of opposed balance weights adjacent the ends thereof, a connector portion between said balance weights, and a longitudinal axis, and said balance weights each having an elongated surface thereon extending in the direction of said longitudinal axis, said method comprising the step of forming at least one elongated recess in said connector portion, said recess being elongated in the direction of said longitudinal axis.
Dependencies are inferred from the claim text.