| 摘要 |
The present invention provides an actuating apparatus for moving relatively rotatable components. In one embodiment the apparatus comprises: a bearing (30) including first (34) and second (36) relatively rotatable bearing elements for mounting respective first (18) and second (12) rotatable components for relative rotation about a common axis; a pneumatic or hydraulic actuator having a pair of co-acting parts (44, 54), including a first part (54) fixed with respect to the said first rotatable element and a second part (44) fixed with respect to the said second rotatable element; and, means (110) for energising and/or de-energising said actuator means to effect movement of the said co-acting parts and thereby relative rotation of the said first and second bearing elements about the said bearing axis. The actuator may comprise at least one chamber (52) defined between a pair of relatively rotatable annular members (44, 54) each having at least one dividing element (66, 68, 70) extending into the chamber to divide the interior of the chamber into separate circumferential regions (80, 82, 84). Pressure differentials generated in the chamber across one or more of the dividing elements effect relative rotation of the first and second bearing elements. |
