摘要 |
A support arrangement for a rotor shaft (10) includes a bearing (28) radially interposed between the shaft and a support frame (26). The bearing has a durable support (100) and a destructible support (104). The destructible support is nested within a circumferentially extending channel (78) having three-dimensionally curved surfaces (82, 84). An adjacent oil seal (44) has similar three-dimensionally curved surfaces (52, 54) In the event that the rotor becomes unbalanced during operation, the destructible support disengages from its housing (76) and glides radially within the channel to restrain the rotor longitudinally while precluding the transmission of imbalance forces from the rotor to the frame. The curved character of the seal surfaces preserves the integrity of the seal so that loss of oil will not prevent continued, low speed operation of the rotor. An optional, temporarily operable damper (148) attenuates especially severe vibrations immediately following the onset of the imbalance. A recentering system (164), also optional, applies a modest restorative force to recenter the disabled rotor and alter its natural frequency thereby inhibiting resonant oscillations at low rotational frequencies. |