Abstract: A rotor assembly for a miniature gas turbine propulsion system comprises a centrifugal compressor wheel, a turbine wheel, a shaft and a tie bolt. The centrifugal compressor wheel includes a first curved tooth coupling, and the turbine wheel includes a second curved tooth coupling interconnected with the first curved tooth coupling. The shaft extends from the centrifugal compressor wheel, and the tie bolt extends between the shaft and the turbine wheel to bring the first curved tooth coupling into compression with the second curved tooth coupling. As such, the compressor wheel and the turbine wheel are assembled and remain, over the operational envelope of the propulsion system, in a reliably robust aligned configuration.

Abstract: A rotor assembly for a miniature gas turbine propulsion system comprises a centrifugal compressor wheel, a turbine wheel, a shaft and a tie bolt. The centrifugal compressor wheel includes a first curved tooth coupling, and the turbine wheel includes a second curved tooth coupling interconnected with the first curved tooth coupling. The shaft extends from the centrifugal compressor wheel, and the tie bolt extends between the shaft and the turbine wheel to bring the first curved tooth coupling into compression with the second curved tooth coupling. As such, the compressor wheel and the turbine wheel are assembled and remain, over the operational envelope of the propulsion system, in a reliably robust aligned configuration.

Abstract: A one-piece housing casting comprising a hub adapted to receive a turbine shaft therethrough and a radially extending flange on the outer periphery of the hub. The flange includes radially aligned annular surface portion and means for spacing the surface a predetermined distance from a radially aligned housing wall close to the outlet of the centrifugal compressor. The flange also includes an axially extended portion having an axially extended surface and means for spacing the surface away from an axially extending surface on a turbine housing wall to define a passage therebetween. Preferably, the means for spacing the walls apart from the turbine housing wall surfaces comprise diffuser vanes integrally formed on the radially and axially aligned surfaces of the flange of the diffuser member.

Abstract: A torque meter is provided for use in conjunction with a layshaft having a forward and rear end and which is rotatably mounted in a housing. The layshaft is axially movable with respect to the housing between a forward and a retracted position while a gearing arrangement in mesh with the layshaft urges the layshaft towards its forward position with a force proportional to the shaft torque. The torque meter comprises a body secured to the housing adjacent the front end of the layshaft which forms a chamber open to the front end of the layshaft while a piston is axially slidably mounted within the chamber. The chamber is pressurized with a fluid, such as oil, which urges the piston against the front end of the layshaft with a force proportional to the pressure so that the piston balances the layshaft against the axial force imposed by the engine. A fluid pressure gauge determines the pressure within the chamber which varies proportionately with the layshaft torque.