GB868806A - Composite rotor for high-temperature steam or gas turbines - Google Patents

Abstract

868,806. Elastic - fluid turbines. SOC. RATEAU. July 11, 1958 [July 12, 1957], No. 22376/58. Class 110 (3). A composite rotor for a high temperature steam or gas turbine is composed of two parts, one part B comprising the high temperature first stage or stages and consisting of a material resistant to those temperatures, and a second part A comprising the following stage or stages and consists of a material of lower heat resistance, the parts being assembled together by means freely permitting their relative expansion. An axial bore in the part B receives a cylindrical extension A 1 on the part A, keys C circumferentially disposed around a radial face of the part A at the downstream end of the rotor engaging with correspondingly shaped recesses in the part B to centralize the parts and transmit torque therebetween. The keys C have radially-extending faces and may be integral with the part A, or screwed to it as shown, when a ring R is fitted to restrain the keys against centrifugal forces. A similar arrangement of keys C<SP>1</SP> is provided at the upstream end of the rotor. Longitudinal registration of the two parts at the upstream end is provided by a ring E, composed of two or more segments mounted in a groove in A and disposed between the end face of the part B and a ring D fixed to that face. Clearance between the faces F, F<SP>1</SP> of the two parts accommodates longitudinal relative expansion. To form a heat barrier between the parts A and B working fluid leaving the last stage of part B enters the annular space between the ports through orifice O 1 and between the faces F and F<SP>1</SP>. The fluid leaves through the orifices O 2 and is lead to a stage downstream of that from which it was taken. A heat-insulating sleeve Z is disposed in the annular space between the parts.