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. 18, 2003
Filed:
Nov. 20, 2000
Jie Yuan, Shrewsbury, MA (US);
James F. Maguire, Andover, MA (US);
Ahmed Sidi-Yekhlef, Westborough, MA (US);
Peter M. Winn, Shrewsbury, MA (US);
American Superconductor Corporation, Westborough, MA (US);
Abstract
A cryogenic refrigerator for cooling a rotating device includes a stationary regenerator, and a rotatable cold heat exchanger coupled to the stationary regenerator to rotate relative thereto. The cryogenic refrigerator is, for example, of the Gifford-McMahon type or pulse tube type. In the Gifford-McMahon type, a stationary cylinder houses the regenerator, and a rotatable cylinder mounted to the cold heat exchanger is concentrically arranged about the stationary cylinder. Alternatively, the rotatable cylinder is axially offset of the stationary cylinder. A seal, for example, a ferrofluidic seal, is located between the stationary and rotatable cylinders. In the pulse-tube type, a pulse tube is concentrically arranged about the regenerator, and the cold heat exchanger includes a stationary portion coupled to the regenerator and a rotatable portion coupled to the pulse tube. A back-up valve system is provided for increased reliability.