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:
Mar. 10, 2015
Filed:
Sep. 29, 2009
Ulf Petersson, Tollered, SE;
Anders Erestam, Gothenburg, SE;
Ulf Petersson, Tollered, SE;
Anders Erestam, Gothenburg, SE;
Husqvarna AB, Huskvarna, SE;
Abstract
An electric motor () having a motor control system () including: —a current measuring means () for directly or indirectly measuring the electric current in the rotor windings () providing a rotor current value/s, —an ambient temperature measuring/estimation means () for measuring or estimating the ambient air temperature providing an air temperature value/s, —a rotor temperature estimation means () for estimating a rotor temperature at least based on the rotor current value/s and the air temperature value/s, and—a current limiting means () for preventing overheating/burning of the rotor assembly () by limiting the electric current to the rotor windings () when the estimated rotor temperature exceeds a predetermined overheating threshold ().