Rearward torque arm for damping independently suspended and driven axle shafts
AssigneeGM Global Technology Operations LLC
InventorsDavid W. Mikels, David M. Caldwell, Young-Jin Seo
Life of this patent
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Abstract
An independently suspended, driven axle shaft set in which the axle shafts are driven by a differential which is rigidly connected to the body of the motor vehicle by a rearward torque arm, whereby powerhop is mitigated thereby. Where the axle shafts are torsionally asymmetric with respect to each other, the differential is a limited slip differential and the relative torsional stiffness therebetween is different by a ratio substantially between about 1.4 to 1 and about 2.0 to 1, wherein powerhop is mitigated synergistically by both the rearward torque arm and the asymmetric axle shafts.
Claims19
A motor vehicle and drive system thereof, comprising:
- a body having a body front end and an oppositely disposed body rear end;
- a first axle shaft;
- a second axle shaft, wherein said first and second axle shafts are independently suspended with respect to said body;
- a differential drivingly connected to said first and second axle shafts;
- and
- a rigid torque arm having a torque arm forward end and an oppositely disposed torque arm rearward end, said torque arm forward end being rigidly connected to said differential and said torque arm rearward end being pivotally connected to said body at a location closer to said body rear end than is said differential, wherein the torque arm rearward end is retained at a fixed spatial distance from the body at the connection;
- wherein said torque arm positively couples vibrations as between said first and second axle shafts by a non-linear coupling of vertical and torsional motions directly to the body so as to thereby decay powerhop oscillations of the first and second axle shafts.
A method of mitigating powerhop in an independently suspended driven axle shaft set of a motor vehicle, comprising the steps of:
- providing a body of the motor vehicle;
- providing first and second axle shafts independently suspended with respect to the body;
- providing a differential drivingly connected to the first and second axle shafts;
- providing a rigid rearward torque arm;
- connecting the rearward torque arm rigidly to the differential;
- and
- pivotally connecting, in a rearward body direction from the differential, the rearward torque arm to the body at fixed spacing from the body;
- wherein the rearward torque arm is selected so that torque oscillations as a function of time are generally out of phase with respect to the first and second axle shafts;
- and
- wherein the rearward torque arm positively couples vibrations as between said first and second axle shafts by a non-linear coupling of vertical and torsional motions directly to the body so as to thereby decay powerhop oscillations of the first and second axle shafts.
Dependencies are inferred from the claim text.