摘要 |
Elimination of a previous intermediate inter-shaft locating bearing allows smaller core sizes to be achieved and avoids relatively sophisticated design complications in order to provide that bearing. Thus, an inner shaft is supported at one end by a mounting bearing and at its other end by a spaced bearing combination upon a static cradle structure. The spaced bearing combination comprises bearings which can be varied in terms of spacing, stiffness of support upon the cradle and sprung resilience in the bearing races in order to tune shaft vibration to avoid critical frequencies occurring in the normal rotational running range of an engine incorporating the arrangement.
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