| 摘要 |
A steady bearing on a mixer shaft in a vessel supported from the walls of the vessel by a plurality of pairs of parallel struts which are pivotably mounted at their ends in fixed parallel clevises, the inner clevises being included in a bearing support subassembly and the outer clevises being attached to the vessel wall. The struts and clevises define a plurality of supportive parallelogram structures. The steady bearing is free to slide axially along the mixer shaft. As the vessel expands or contracts in response to changes in internal pressure or temperature as required by process conditions, the shape of the parallelogram structures is free to change to lengthen or shorten the parallelogram diagonals, and in response the steady bearing moves to a new position along the shaft. Radial support of the bearing is maintained at all axial positions assumed by the bearing. The inner clevises are mounted on a clevis carrier which is attached to the bearing holder only through rings at the top and bottom of the holder. The struts and clevises are provided with cooperating faces which can interfere in the event of mechanical failure of the pivot pins to arrest a loose strut and prevent it from catastrophically engaging the mixer impeller. In a similar fashion, this interference prevents the steady bearing assembly from dropping down the shaft, which due to the strut geometry, would cause the shaft to be pulled to the side causing failure of the shaft and/or its supporting components. |
