System and method for inertial torque reaction management

Abstract

A system and method for managing inertial torque reactions on stationary powertrain structure rotate at least one selected engine component and at least one selected drive train component in opposite directions so the rotational inertia of the selected drive train component acts in a direction opposite to that of the rotational inertia of the selected engine component to reduce or eliminate the inertial torque reactions on stationary powertrain structure caused by rotational acceleration and deceleration of powertrain components and improves performance with respect to noise, vibration, and harshness (NVH).

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to systems and methods for managing inertial torque reaction of rotating machines. [0003] 2. Background Art [0004] A conventional powertrain has a “stationary” structure that is attached to the vehicle chassis with resilient mounts. In conventional powertrains, rotating inertia of various engine and transmission components including the crankshaft, flywheel, and torque converter of an automatic transmission, for example, is rotated in the same direction, having a compounding effect. When a compression or combustion event of the engine causes an acceleration of the rotating inertia, generally, there is an equal but opposite inertial torque reaction imposed upon the stationary structure. As such, the stationary structure is not truly stationary, but instead, vibrates in opposition to the accelerations of the rotating inertia. This vibration of the stationary structure passes vibration thr...

AI Technical Summary

Benefits of technology

[0009] In a transversely mounted internal combustion engine and transaxle, as generally used in, but not limited to, front wheel drive (FWD) vehicles, for example, the crankshaft and the torque converter may be connected using toothed wheels enabling the torque converter and crankshaft to rotate in opposite directions. A separate or integrated device may be used to reduce or eliminate backlash and associated noise, such as a scissors gear, for example. The opposing direction of rotation of the crankshaft and torque converter reduces or eliminates the inertial torque reaction on the stationary powertrain structure to reduce or eliminate unwanted vibration and noise.

[0010] A longitudinally mounted engine and transmission application, as generally used in, but not limited to, rear wheel drive (RWD) vehicles, for example, may incorporate a simple planetary gear set to connect the crankshaft to the torque converter. Such a planetary gear set typically includes a sun gear, a ring gear, and a carrier with a plurality of pinions that are constantly in mesh with the sun and ring gears. In such an arrangement, for example, the carrier may be rendered stationary by using a plurality of fasteners to connect it with the engine/motor block. The sun gear of the planetary gear set may be connected to the crankshaft using any of a variety of methods including using conventional fasteners or alternatively splines with at least one retaining ring. Likewise, the ring gear or the annulus of the planetary gear set may be connected to the engine/motor flex plate using a plurality of fasteners. Such an arrangement allows the ring gear to rotate in a direction opposite to that of the sun gear when the carrier is

Problems solved by technology

This vibration of the stationary structure passes vibration through the resilient mounts into the vehicle chassis, and may result in unwanted noise and vibration within the vehicle passenger compartment.

However, the constraints placed on the engine/powertrain operation may impact the abilit

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