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:
May. 22, 2012
Filed:
Nov. 24, 2008
David M. Fee, Groveland, IL (US);
Matthew A. Gregait, Metamora, IL (US);
David M. Fee, Groveland, IL (US);
Matthew A. Gregait, Metamora, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
An electric motor such as an AC induction electric motor includes a rotor having a rotor core and a rotor shaft. The rotor shaft defines an axially extending bore which has an electrical grounding ring positioned therein. The electrical grounding ring has an inertia insensitive configuration and forms a relatively low resistance electrical circuit segment between the rotor shaft and an electric motor housing to ground the electric motor rotor. The electric motor includes an oil lubricated bearing for the rotor shaft, and a sealing member such as a lip seal is positioned within the axially extending bore to inhibit lubricating oil intrusion therein. A non-rotating stub shaft may be mounted in the housing and extends into the axially extending bore to fluidly seal with the sealing member and electrically connect with the electrical grounding ring, which is fixed to rotate with the rotor shaft.