GB765021A - Improvements in or relating to gas turbines - Google Patents

Abstract

765,021. Gas turbine plant; elastic-fluid turbines. UNITED AIRCRAFT CORPORATION. March 4, 1955, No. 6526/55. Class 110 (3). [Also in Group XXXIV] In a gas turbine plant comprising a lowpressure, multi-stage axial-flow compressor and a propeller driven by one turbine section and a like high-pressure compressor driven by a highpressure turbine section, the high-pressure compressor 152 is supported by a bearing 170 which is carried by a housing 172 positioned by struts 174 through which accessory drive-shafts 176 extend. Cooling air from the compressor is fed through holes 252 into a space 253 defined by the wall 216 of the combustion chamber, a member 184 and a diaphragm 254 which may have nozzles 256 for directing the air against the turbine disc. Bearings 170, 180 are enclosed within the housing 172, a ring 186 and a sleeve 262 which surrounds the shafts 88 and 182 to define a chamber 264 closed by seals 266, 270. Lubricant is supplied to the chamber 264 through pipes 272, 274 and 276 and recirculated through a duct 278 connected to a scavenge pump (not shown). The stub shaft 142 of the turbine disc 72 is journalled in a bearing 140 which is supported in a spider 144 splined to an outer ring 148, the splined connection permitting relative radial expansion between the associated members. Lubricant is fed to the bearing 140 through a pipe 286 and recirculated through a tube 288. A housing 294 surrounds the bearing housing 290 and is fed with ram air through a duct 298, the housing 290 being vented by a pipe 300. A starter motor 312 is provided which drives a gear 320 in mesh with a gear 322 on one of the accessory drive-shafts 176. Certain accessories such as the scavenge and oil pressure pumps may be driven in conjunction with the low-pressure unit. The end bells such as 162 of the compressor are located axially inwardly of the outermost compressor discs whereby the overall length of the rotor may be shortened and the stator blades of the compressor are mounted on L-shaped plates which are clamped between the adjacent casing sections, see Fig. 6 (not shown). Heat shields 220, 222 line the casing 208 and the sleeve 216 respectively, both shields being spaced from the adjacent part to permit a flow of cooling air therethrough. Additional heat shields 236, 238 are located between the nozzle-supporting ring 232 and the burners. A propeller shaft 12 is journalled in bearings 14 and a member 26 which is splined to a gear 40 connected, as by a loose-splined ring 42, to a sun-gear 44 journalled on the shaft 12. The sun gear 44 meshes with pinions 47 which are carried by a cage 48 and also mesh with a ring gear 52. A gear 58 is also splined to the cage 48 and forms the sun-gear of a second planetary reduction gear including pinions 60 carried by a cage 62 splined to the shaft 12. The pinions 60 mesh with a ring gear 64 clamped to the frame. work of engine. Specification 618,635 is referred to.