| 摘要 |
A cantilever structure (e.g. windmill sails 1 carried by a nacelle 3) is supported at the top of an upright structure (a tower 4) for rotation about a vertical axis by a bearing and driving assembly comprising first support means 9A/9B/10/14 acting vertically in use for supporting the cantilever structure 1/3 against dropping down the upright structure 4, second support means 16A-16D acting horizontally when operative in use to lock at a selected position the cantilever structure 1/3 against rotation about the vertical axis, and third support means 17A-17D actuable to act horizontally in use in place of the second support means and, whilst so acting, to move to rotate the cantilever structure 1/3 about the vertical axis. The second and third support means include pads 16A-16D and 17A-17D and vertical surfaces that are in frictional engagement when these support means are operative, the use of conventional rotational bearing elements in the second and third support means, which would have to be of much larger size than the pads for similar loadings, being avoided. <IMAGE> |
