| 摘要 |
1,065,278. Axial-flow compressors; compressor blades. ROLLS-ROYCE Ltd. Sept. 4, 1964, No. 36436/64. Headings F1C and F1T. In an axial-flow compressor for a gas turbine jet propulsion engine, the radially outer ends of the first stage stator blades are attached to the casing and the radially inner ends are disposed adjacent an abutment mounted on the rotor whereby axial movement of the stator blades is restricted. The compressor shown comprises first-stage stator blades 26 brazed or welded at their outer ends into slots in the casing 16 and brazed or welded at their inner ends into a ring 50. An annular abutment 52 on the ring 50 has a small axial clearance from an annular abutment 53 on the outer race of a ball bearing 54, the inner race being fixed on a rotor hub 20. Inlet guide vanes 24 carry the outer race of the front bearing 23 of the rotor, an annular abutment 7 on the outer race being disposed upstream of an annular abutment 8 on the rotor. Should a bird strike the inlet guide vanes 24, their resultant axial deflection is limited by the abutment 7 coming into contact with the abutment 8. The number of the vanes 24 is increased beyond the usual number and their leading edges are sharpened to cut the ingested bird into small pieces, whereby subsequent blades suffer less damage. Similar provision is made in the case of the stator blades, which are reduced in chord so that they retain their standard profile and space chord ratio despite their increased number and their sharper leading edges. The reaction of the pieces of bird on the stator blades 26 causes them to move forwardly until abutment 52 abuts the abutment 53 to limit the movement. Abutment 53. and the outer race of the bearing 54 then stop rotating. Each rotor blade 25, 27 is fixed to the rotor by a dowel pin 34 which is a close fit instead of the usual loose fit allowing the blade some freedom to roll. In addition, the abutting faces of adjacent blade roots are serrated to lock the rotor blades together to resist deflection in a circumferential direction. Adjacent blades are interconnected by aerofoil struts 37, 51. Rotor blades 25, 27 and, it may be, stator blades 28 are of titanium. |
