The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 11, 2006
Filed:
Jul. 17, 2003
Michael G. Onsager, Franklin, WI (US);
Carl D. Gilmore, South Milwaukee, WI (US);
Walter Koellner, Suwanee, GA (US);
Michael G. Onsager, Franklin, WI (US);
Carl D. Gilmore, South Milwaukee, WI (US);
Walter Koellner, Suwanee, GA (US);
Bucyrus International, Inc., South Milwaukee, WI (US);
Abstract
A dragline excavating machine includes a gearless direct drive AC drive motor for driving each of the hoist and the drag drums in the system. The gearless AC motor is driven using a digital system which receives AC power from the utility system rectifies the power using active front end circuits, and converts the resultant DC to a frequency controlled AC using an inverter circuit. The resultant AC signal is employed to drive the gearless AC motor, resulting in reduced harmonic distortion, unity or leading power factor, and increased efficiency, reduced operating costs, and reduced mean time between failure.