Ceramic rotor and manufacturing process therefor

Claim 1

A process of producing a ceramic rotor, comprising steps of preparing at least one mixture consisting of 100 parts of ceramic powder and 0.1 to 20 parts of sintering agents which are active during sintering at atmospheric pressure, forming a body of blade portions of integral structure from said mixture by one of injection molding and casting, forming a body of a blade-holding portion by casting said mixture in a metal mold and applying isotropic compression to the thus cast body so as to cause said blade-holding portion to have a larger density after sintering than that of said blade portions after sintering, applying ceramic paste to those surfaces of said body of blade portions and said body of blade-holding portion which are to be cemented, coupling said bodies at said pasted surfaces, and sintering the thus coupled bodies in an atmosphere selected from the group consisting of nitrogen and inert gases at atmospheric pressure so as to produce a ceramic rotor of unitary structure with said blade portions integrally cemented to said blade-holding portion along a cemented surface therebetween in such a manner that, said blade portions have front surfaces defining a first plane and rear surfaces defining a second plane, said second plane intersecting a central axis of said rotor at a first point and being spaced from said first plane by a distance d 3 along said central axis, and said blade portions have interblade center lines defining a curved surface surrounding said central axis, said cemented surface is located between said curved surface and said central axis so that a distance d 1 from an arbitrary point on said cemented surface to said first point along a straight line therebetween is smaller than said distance d 3 but not smaller than a distance d 2 from said arbitrary point on said cemented surface to said curved surface taken along said straight line, namely, d 1 <d 3 and d 1 ≧d 2 .