| 摘要 |
1,085,329. Turbines. GARRETT CORPORATION. Jan. 21, 1965 [Jan. 21, 1964], No.2743/65. Heading FIT. [Also in Division F2] A turbine or other high speed rotary machine includes a rotor having one or more rotary elements and means for containing fragments of the rotary elements in the event of separation thereof from the rotor due to centrifugal force, the means including an annular shield having an inwardly facing groove aligned with the elements, the shield being capable of rotation by forces imparted thereto by separated fragments, a shroud closing the groove during normal operation. A hot gas or air turbine has a rotor disc 12 having a region 29 of reduced axial thickness so that at a predetermined rotor overspeed a platform 13 carrying the blades 14 will separate from the disc body 10 and be caught by a containment device 30 surrounding the rotor. Alternatively, blades 14 may be weakened so that they become detached from platform 13 under overspeed conditions. Device 30 includes an annular channel section shield 31 of impact resistant material, such as titanium, and an annular shroud 33 which closes the channel of shield 31 and is frictionally clamped, together with the shield, between turbine casing portion 19 and a ring 18 located by an annular flange 23 on casing portion 17. Ring 18 also supports nozzle guide vanes 26. In the event of disintegration of the rotor, the fragments penetrate shroud 33, to enter the channel of shield 31. Remaining fragment energy may be dissipated in causing rotation of shield 31 and/or shroud 33 against the frictional resistance provided by clamping bolts 32. In a modification, Fig. 2 (not shown), the channel of shield 31 is lined with a soft material such as aluminium to absorb further fragment energy. In the case of a turbine operating with relatively cool air or gas shroud 33 may be omitted, Fig. 3 (not shown), and the shroud formed by a soft liner (35a) welded in segments in the shield channel or frictionally engaged therein. |
