Method and apparatus for balancing a vehicular driveshaft

Abstract

A method and apparatus for quickly and efficiently balancing an article, such as a tube for use in a vehicular drive shaft assembly, for rotation about an axis is provided. Initially, a balance ring is press fit or otherwise mounted onto the article to be balanced. The balance ring includes a ring of a material that can be selectively removed to balance the article for rotation, such as powdered metal. The article is mounted on an apparatus for rotating the article at a predetermined speed and for sensing vibrations that are caused by imbalances in the structure of the article. An electronic controller is responsive to such sensed vibrations for determining the size and location of one or more balance weights that, if secured to the article, will minimize or eliminate these imbalances. The electronic controller actuates a source of energy, such as a laser, to alter the physical properties (such as by hardening, for example) of only those portions of the ring that correspond with the size and location of the balance weights that will minimize or eliminate the imbalances therein. Thereafter, the unhardened portions of She ring are removed, leaving only the hardened portions thereof as the balance weights.