Gear coupled, counter-rotating vibratory drive assembly

Claim 1

A gear coupled, counter-rotating vibratory drive assembly comprising: a housing for operatively connecting to a device to be vibrated in a desired linear motion; said housing having a prescribed length with an elongated central gear box compartment formed therein; a drive shaft extending through the gear box compartment and rotatably supported by drive shaft support bearings for rotation about a drive shaft axis; said drive shaft having a central gear section intermediate the drive shaft support bearings and end section extending outward from the central gear section and the drive shaft support bearings exterior of the gear box compartment; a drive gear having a prescribed diameter mounted on the central gear section for rotation with the drive shaft within the gear box compartment; a driven shaft extending through the gear box compartment and rotatably supported by driven shaft support bearing for rotation about a driven shaft axis that is parallel with the drive shaft axis; said driven shaft having a central gear section intermediate the driven shaft support bearings and end sections extending outward from the central gear section and the driven shaft support bearings, exterior of the gear box compartment; a driven gear mounted on the central gear section intermeshed with the drive gear for rotating the driven shaft at the same angular speed but in a direction counter to the drive shaft; eccentric weights mounted on the end sections of both the drive shaft and the driven shaft for rotation therewith in counter-rotating directions about the shaft axes in phased angular relationship to generate vibrational linear motion; each of the eccentric weights having a prescribed peripheral radius from the respective shaft axis that is less than the prescribed diameter of the drive gear but greater than one-half the prescribed diameter of the drive gear wherein the eccentric weights on the drive shaft are mounted axially offset with respect to the eccentric weights on the driven shaft so that the eccentric weights rotate in noninterfering paths; and wherein one of gears has metal teeth and wherein the other gear has a metal hub with a plastic gear ring mounted on the hub in which the plastic gear ring has plastic teeth engaging the metal teeth of the one gear.