| 摘要 |
1,012,066. Turbine rotors. GENERAL ELECTRIC CO. June 20, 1963 [July 11, 1962], No. 24670/63. Heading FIT. A turbine rotor disc has circumferentially spaced axially extending, fir-tree slots in the rim carrying long shanked blades, the roots of the blades having an axial length less than that of the slots to permit cover plates to fit into the slots with the blade roots, the plates blocking the spaces between the blade shanks. A turbine rotor disc 1, Fig. 1, carries in axial fir-tree slots 2 blades 3 having platforms 5, shanks 6 and roots 7. The axial length of roots 7 is less than that of slots 2, Fig. 6, so that segmental cover plates 8, also having fir-tree roots 9, may fit within the slots on either side of roots 7. Plates 8 comprise axially inner and outer plates, 15, 16 respectively, Fig. 3, which overlap at 15a, 16a to seal the spaces between shanks 6. Outer plates 16 carry lips 18 locating in a circumferential groove in blade platforms 5 but inner plates 15 terminate radially inwardly of platforms 5 at 17. Plates 15, 16 are notched at 11 to receive cylindrical pins 12 which lock platforms 5 together centrifugally. Roots 9 of plates 8 are retained axially by a strip 13 locating in a circumferential groove 1b in disc rim 1 and grooves 9b in roots 9. Pins 14 lock strip 13 in position. The construction reduces the effects of centrifugal bending moments resulting from axially offset cover plates. In a modification, the cover plates are identical and overlap consecutively. |
