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:
Jan. 29, 1991
Filed:
Mar. 10, 1989
Hitachi, Ltd., Tokyo, JP;
Abstract
A gas turbine includes a turbine stubshaft, a plurality of turbine disks coupled to the shaft by turbine stacking bolts with spacers interposed therebetween, turbing moving blades planted in each of the disks, a shroud provided with a sliding surface in a spaced-apart relation to the tips of the moving blades, a distant piece connected to the disks by the bolts, a plurality of compressor disks coupled to the distant piece by compressor stacking bolts, compressor blades planted in each of the compressor disks, and a compressor stubshaft formed integrally with the compressor disk located at the first stage. At least a sliding portion of the shroud is made of a heat-resistant cast alloy having in turn a chilled layer and columnar grains in a direction oriented from the sliding surface thereof toward the interior thereof. A method of producing a segment-shaped shroud for a gas turbine by casting, comprises the steps of preparing a mold having a coated layer formed on at least a surface thereof which is to be in contact with a casting, the coated layer containing refractory aggregate powder at a main constituent, and refractory agent powder for accelerating generation of crystal nuclei, pouring the molten alloy into the mold, and forced-cooling the outer surface of the mold.