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:
Nov. 29, 2011
Filed:
May. 29, 2009
Donald R. Davis, Brighton, MI (US);
Nicolaus a Radford, Houston, TX (US);
Frank Noble Permenter, Webster, TX (US);
Adam H Parsons, Houston, TX (US);
Joshua S Mehling, League City, TX (US);
Donald R. Davis, Brighton, MI (US);
Nicolaus A Radford, Houston, TX (US);
Frank Noble Permenter, Webster, TX (US);
Adam H Parsons, Houston, TX (US);
Joshua S Mehling, League City, TX (US);
GM Global Technology Operations LLC, Detroit, MI (US);
Abstract
An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.