Gm Global Technolgoy Operations, Inc.

Paul A Piorkowski

Julian R Verdejo

Qi Ma

Gary L Stecklein

Bapiraju Surampudi

Michael J Grimmer

Mark A Gehringer

Eric J Defenderfer

Robert A Muchmore

Joe Steiber

David T Stark

Michael S Powell

Alfonso G Hysko

Stephen H Miller

Michael Partridge

Michael R Rosati

Stephanie A Erntser

Steven D Nash

Robert M Senseney

Marlin R Turbett

Matthew S Castiglione

Benjamin A Treichel

David L Joseph

Robert W Tator

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.

Driveshaft with two-stage stiffness

An axle-shaft system for transmitting torque in a motor vehicle drive-train includes first and second two-stage stiffness axle-shafts. Each axle-shaft includes a hollow cylinder having first and second ends and a hollow cylinder stiffness. The axle-shaft also includes an inner shaft extending through the hollow cylinder, and having first and second ends and an inner shaft stiffness. The inner shaft's and the hollow cylinder's first ends are engaged via a rotational clearance fit. The inner shaft's and the hollow cylinder's second ends are rotationally fixed to permit the inner shaft's first end to twist relative to the inner shaft's second end. The inner shaft's stiffness defines the axle-shaft's first-stage stiffness, while the inner shaft's and the hollow cylinder's combined stiffness defines the axle-shaft's second-stage stiffness. At least one of the first-stage and second-stage stiffness of the first axle-shaft is dissimilar from the respective stiffness of the second axle-shaft.

Axle-shaft system with two-stage stiffness and side-to-side stiffness bias

A selectable mass flywheel assembly for a powertrain of a motor vehicle includes a first mass and a second mass. The first mass is connected to a crankshaft of an engine and the second mass engages with a clutch to transfer torque from the engine to a transmission. The two masses are rotationally coupled to each other with a spring and damper assembly. The flywheel assembly further includes a locking mechanism that engages both masses during the startup of the engine to lock the two masses together to minimize the vibrations and pulsations in the powertrain during startup of the engine.

Selectable mass flywheel

A method and system for controlling an engine function includes a deflection determination module generating a clutch deflection signal. The system further includes an engine function module controlling an engine function in response to the clutch deflection signal. The clutch deflection signal may be generated by sensors associated with the transmission shaft such as within the clutch housing or the friction disk.

Method and system for determining engine brake torque in real time

The virtual vehicle transmission test cell includes an electric motor which simulates a fuel driven engine, an output motor which simulates the load a transmission experiences in a vehicle, and an environmental element which controls the ambient environment of the transmission and the temperature of the transmission oil within the transmission. The virtual vehicle transmission test cell reduces in-vehicle testing, reduces testing with fuel-driven test cells, and enables development of a transmission design before a corresponding engine is completed and built for testing.

Virtual vehicle transmission test cell

Growing community of inventors

Belleville, MI, United States of America

Paul A Piorkowski