Patent GB-1159768-A (GB)
Title: Gas Turbine Engines.
IPC: F02C7/105
Filed: 1968-04-18
Abstract: 1,159,768. Thermal regenerators. GENERAL MOTORS CORP. 18 April, 1968 [25 May, 1967], No. 18402/68. Heading F4K. [Also in Division F1] The invention relates to a gas turbine engine which incorporates a rotary regenerative heat exchanger, the regenerator comprising a matrix rotatably mounted within a casing which is mounted on and supported by the engine with freedom for expansion with respect thereto. The engine comprises a compressor 5 which supplies air through a diffuser outlet 34 into two casings 68 disposed one at each side of the engine, each casing containing a rotary heat exchange matrix 66. The air is heated in passing through the matrices and passes to two combustion chambers 10 to which fuel is supplied by injectors 55, the combustion gases passing into a common duct 54 from which they pass to a high pressure turbine located within casing 45, the turbine shaft 60 being connected to the compressor shaft 64 through coupling 63. The gases then pass to a low pressure turbine also disposed within casing 45, the turbine shaft 57 driving the output shaft 58 through reduction gearing disposed in gear case 8. The turbine exhaust gases discharge through diffuser 59 and then pass through the heat exchanger matrices 66 finally discharging through outlets 11 at the upper part of the regenerator casing 67. The engine is supported at the rearward end by means of a yoke 19 having mountings 21 for trunnions 22 which project from each side of the gear case 8. The rectangular section frame member 15 is supported by means of a pair of struts 27 with a crosspiece 26, the support affording a universal joint. An auxiliary drive case 14 is secured to the member 15 and the compressor 5 is supported thereon by means of a pair of pivotally mounted links 30, a key 31 secured to the compressor casing engaging a slot in bracket 33 secured to the case 14 for further support. The engine which may be utilized as a power unit for a locomotive is thus supported at three points. The turbine casing 45 is surrounded by a solid ring member 46 of rectangular crosssection, the turbine casing being supported therein by means of four keys 47 which slidably engage recesses 49 formed in the inner periphery of the ring member. The turbine casing is located axially by means of four links 50 pivotally connected to brackets 51 on the casing and on the ring member 46. The ring member 46 and the turbine assembly is located within a rectangular shaped frame comprising two members 17, 18 each of hollow rectangular cross-section, secured together at top and bottom, the ring member 46 being secured at top and bottom to the member 17 of the rectangular frame. A compressor shaft housing 29 is secured to the shaft housing portion 28 of the frame member 17. A shaft housing 53 of the frame member 17 surrounds the turbine shaft 60, the shaft being supported in bearings 61, 62. A heat shield 102 surrounds the shaft housing 53. A shaft housing 65 of the frame member 18 surrounds the power turbine shaft 57, a heat shield 105 surrounding the shaft housing. A bulkhead 85 of rectangular shape surrounds the turbine casing 45, the bulkhead being of hollow form and comprising end walls 87, 89 which have circular apertures to receive the turbine casing, and top and bottom walls 91, 90, the sides of the bulkhead being open for inflow of cooling air, a baffle 180 being located adjacent each open side. Sealing means 93 and 98 respectively are provided between the end walls 87 and 89 of the bulkhead and the turbine stator casing 45. The regenerator casings 68 with the regenerator matrices 66 therein are secured at each side of the engine, each regenerator comprising an inner wall 78, a circumferential wall, 76, a removable outer cover-plate 122 and a rotary matrix 66 which is supported by means of rollers 163 engaging against the inner peripheral portion of the matrix. The matrix is rotated by means of one of the rollers 163 which is driven from the compressor drive turbine shaft 60 by means of gears 153, 154, 155, 156, shaft 158, bevel gearing 159, gears 160 and shaft 165. A main seal 86 is associated with the lower roller 163 and a second seal 86 is associated with the upper roller (not shown). Seals 151 are also provided adjacent the inner peripheral portion of the rotary matrix at both sides thereof to prevent air or gases by-passing the matrix. A coverplate 125 housing a fuel burner 55 and igniter 126 is secured to the cover-plate 122 in alignment with the combustion chamber 10. The cover-plate 122 is strengthened by ribs 129 in the high pressure region adjacent the compressor outlet. The cover-plates are also strengthened by means of a hollow tubular member 131. A fan 170 driven from the gear 156 by shaft 171 is provided for drawing ambient air through the engine for cooling purposes. Means are provided for supporting the regenerator casing 68 from the engine for assembly and disassembly, a bracket 139 being secured to the frame member 17, a shaft being located in openings 141 in the bracket, each casing 68 having a corresponding ring member 142 which is guided on to the shaft, the shaft being subsequently removed and the ring 142 closed off by a plate 146. The main seals 86 extend between the bulkhead 85 and the peripheral wall 76 of the casing. Each heat exchanger casing 67 is supported at the rearward end by means of a supporting foot 109, 110 which is slidably mounted on a plate 111 secured to the reduction gear case 8. The rearward end of the regenerator casing is aligned laterally of the engine by a slot and key assembly 113, 114. Fore and aft location of the regenerator casing is achieved by means of keys, not shown, which extend from the upper and lower arms of the main frame member 17 and which engage in keyways 117 in bosses 118 secured to the inner wall 78 of each regenerator casing 68. The forward end of each casing 68 is supported on the shaft housing 28 of the main frame member 17 by means of a split ring member 71 which can slide axially thereon.