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:
Sep. 15, 1992
Filed:
Aug. 19, 1991
William T Beale, Athens, OH (US);
Robert W Redlich, Athens, OH (US);
Sunpower, Inc., Athens, OH (US);
Abstract
The invention relates to thermomechanical transducers drivingly linked to a linear motor or alternator, preferably a free piston Stirling engine in which the piston is drivingly linked to the field magnet of an alternator. There are symmetric and coaxial secondary magnets attached at opposite ends of the field magnet. The field magnet is polarized radially in one direction and the secondary magnets are polarized radially in the opposite direction. When the field magnet is displaced from a centered position, the secondary magnets have an oppositely directed axial net force exerted upon them. This causes a centering bias on the field magnet and therefore a centering of the piston in the Stirling engine or cooler. A secondary effect produced by the magnetic spring of the secondary magnets is amplitude limiting during load reduction on the Stirling engine. Amplitude limiting is a result of increased spring constant of the magnetic spring past a certain amplitude. This increased spring constant results in greater energy storage in the magnetic spring and decreased efficiency due to decreased phase angle.