US 6,645,108 B1 · Active torque bias system and controls

Abstract

An automotive vehicle has wheels on primary and secondary axles to which power from a motor and transmission is delivered through a transfer case. The transfer case apportions the torque between the primary and secondary axles to best suit the conditions under which the vehicle operates. The torque for the primary axle passes through the transfer case without experiencing slippage. The torque for the secondary axle is extracted at a torque bias coupling which includes a magnetic particle clutch and planetary gear set organized such that two paths exist through the coupling—one a clutch path in which slippage occurs and the other a mechanical path in which no slippage occurs. Most of the extracted torque passes through the mechanical path, but the magnetic particle clutch controls the amount of the torque extracted by the coupling. That coupling dissipates power as a consequence of the slippage in it, and a controller monitors the operation of the clutch to insure that the power dissipation, which manifests itself as heat, does not exceed prescribed limits.

Claims22

Dependent claims

In an automotive vehicle having primary and secondary wheels on primary and secondary axles, respectively, and a power unit that produces torque, the improvement comprising:

a transfer unit including;
an input connected to the power unit;
a primary output coupled with the input such that no slippage occurs between them;
a secondary output;
and
a torque bias coupling connecting the input with the secondary output and including a clutch and a planetary gear set coupled such that torque will transfer through the coupling in two paths, one a clutch path in which slippage occurs and the other a mechanical path in which no slippage occurs, with most of the torque passing though the mechanical path;
and
a controller which monitors the torque transmitted through the coupling and insures that slippage within the clutch of the clutch path does not produce a power dissipation which exceeds a prescribed limit.

5 more elements

Dependencies are inferred from the claim text.

Active torque bias system and controls

Life of this patent

Active torque bias system and controls

Life of this patent

Abstract

Claims22