US 2016/0238083 A1 · DRIVESHAFT WITH TWO-STAGE STIFFNESS

Abstract

A two-stage stiffness driveshaft includes a hollow cylinder having first and second ends and a hollow cylinder stiffness. An inner shaft having first and second ends and an inner shaft stiffness extends through the hollow cylinder. The inner shaft's first end and the hollow cylinder's first end are engaged via a rotational clearance fit. The inner shaft's second end is rotationally fixed to the hollow cylinder's second end to permit the inner shaft's first end to twist through a predetermined angle relative to the inner shaft's second end. The inner shaft's stiffness defines the driveshaft's first-stage stiffness, while the combined stiffness of the inner shaft and the hollow cylinder defines the driveshaft's second-stage stiffness. A damping element positioned between the inner shaft and the hollow cylinder controls variation in torque transmitted by the driveshaft and generates gradual transition between the first-stage stiffness and the second-stage stiffness.

Claims20

Dependent claims

A two-stage stiffness driveshaft for transmitting an input torque, the two-stage stiffness driveshaft comprising:

a hollow cylinder defined by a longitudinal axis, a first end, and a distal second end, and having a hollow cylinder stiffness;
an inner shaft extending through the hollow cylinder along the longitudinal axis and defined by a first end, and a distal second end, and having an inner shaft stiffness;
and
a first damping element arranged between the inner shaft and the hollow cylinder and configured to control variation in the input torque transmitted by the driveshaft;
wherein:
the first end of the inner shaft is engaged with the first end of the hollow cylinder via a rotational clearance fit;
the second end of the inner shaft is rotationally fixed to the second end of the hollow cylinder such that the first end of the inner shaft will twist to a predetermined angle with respect to the second end of the inner shaft in response to the input torque;
the inner shaft stiffness defines a first-stage stiffness of the driveshaft and the inner shaft stiffness together with the hollow cylinder stiffness defines a second-stage stiffness of the driveshaft;
and
the first damping element is configured to generate a gradual transition between the first-stage stiffness and the second-stage stiffness.

7 more elements

A drive-train for a motor vehicle comprising:

a power-plant configured to generate torque;
a road wheel;
and
a two-stage stiffness driveshaft configured to transmit the torque from the power-plant to the road wheel, the driveshaft including:
a hollow cylinder defined by a longitudinal axis, a first end, and a distal second end, and having a hollow cylinder stiffness;
an inner shaft extending through the hollow cylinder along the longitudinal axis and defined by a first end, and a distal second end, and having an inner shaft stiffness;
and
a first damping element arranged between the inner shaft and the hollow cylinder and configured to control variation in the torque transmitted by the driveshaft;
wherein:
the first end of the inner shaft is engaged with the first end of the hollow cylinder via a rotational clearance fit, and is configured to receive the torque from the power-plant;
the second end of the inner shaft is rotationally fixed to the second end of the hollow cylinder such that the first end of the inner shaft will twist to a predetermined angle with respect to the second end of the inner shaft in response to the torque received from the power-plant;
the inner shaft stiffness defines a first-stage stiffness of the driveshaft and the inner shaft stiffness together with the hollow cylinder stiffness defines a second-stage stiffness of the driveshaft;
and
the first damping element is configured to generate a gradual transition between the first-stage stiffness and the second-stage stiffness.

11 more elements

Dependencies are inferred from the claim text.

Driveshaft with two-stage stiffness

Life of this patent

Driveshaft with two-stage stiffness

Life of this patent

Abstract

Claims20