Patent GB-775454-A (GB)
Title: Improvements in or relating to engine supercharging device
IPC: F01D5/02
Filed: 1954-05-20
Abstract: 775,454. Gas turbines; centrifugal compressors; stuffing-box substitutes. GARRETT CORPORATION. May 20, 1954 [June 8, 1953], No. 14812/54. Classes 110 (1), 110 (3) and 122 (5). [Also in Group XXXIV] In an exhaust driven supercharger the turbine nozzle mechanism is flexibly mounted. The mounting comprises a thin ring 78, Fig. 1, with flanges 77, 79. The flange 77 is secured between the flanges of the housing 11 and the scroll 63 supplying the exhaust gases. The flange 79 is secured to a plate 81, in which the nozzle vanes 87 are adjustably mounted, by studs 82 also employed to unite the plate to a shroud ring 67 for the turbine blades 61. The shroud ring has an axial extension carrying sealing rings 70 engaging the wall of the exhaust outlet from the scroll. A snap ring 72 in the opening provides a stop for a suitable discharge duct that may be mounted in the opening. Each nozzle vane, Fig. 4, is of air-foil shape and is secured at the trailing edge 90 at some distance from the axis of a disc 88 on the end of a shaft 91 journalled in a boss 84 in the plate 81. An arm 92 radially secured on the shaft by serrations and a snap ring has a slotted end engaging a pin 96 carried by a nozzle actuating ring 97 supported on rollers 101 mounted on shaft 99 journalled in the housing. Circumferential slots 104 in the ring make the support resilient. A shaft 110 journalled in the housing carries an actuating arm 115 and an arm 106 engaging a notch in the actuating ring 97. Heat shields 118, 116 protect the actuating mechanism. A modification of the actuating mechanism is described (see Figs. 5 and 6, not shown). A connection 140 from the compressor outlet scroll creates a pressure in the chamber formed between the shields and the housing and the high pressure air is bled away between the shafts 91 and the bores in which they are journalled, to the downstream side of the nozzle vanes. The compressor rotor 31 and turbine rotor 56 are mounted on a shaft 20 carried in bearings 18, 19 arranged in a carrier 14 secured in the housing 11 and provided with a lubricating connection 130. The carrier and housing are both made in halves to facilitate assembly. The flanges of the bearing 18 are engaged by a shoulder 24 and a flange 28 on the shaft to take the thrust loading. A ring 32 mounted on the shaft 20 engages the flange 28 and the walls of an annular recess in the rear face of the wheel. A shear pin 41 mounted in the ring engages apertures in the flange and the wheel. The ring 32 and the inlet end of the rotor shroud 44 are engaged by labyrinth seals 47 and 119 respectively. The seal 47 is retained in position in the air inlet 51 by a snap ring 49. The seal 119 is retained in a flange 12 in the housing by threads 121 allowing longitudinal adjustment of the seal, the edges of the latter co-operating with steps in the ring 32. The turbine rotor 56 is bolted to a flange 55 secured to or formed on the shaft 20. A spacer ring 57, with radial grooves to limit heat transfer, is arranged between the flange and the rotor hub and is stepped to co-operate with a seal 120, arranged in a recess in the housing 11, and additionally held against rotation by a pin 124. Specifications 775,455 and 775,456 are referred to.