| 摘要 |
<p>Locking device locking the suspension nut of a driven shaft from rotation relative to the shaft, upon reversal in the direction of rotation of the shaft or such vibration as would loosen an ordinary nut. The locking device is particularly adapted for cantilevered shaft vertical pumps in which the shaft and pump impeller on the end of the shaft are susceptible to vibration. The locking device includes a pump coupling including a motor shaft coupling part and a pump shaft coupling part detachably secured to the motor shaft coupling part. A nut part having a cylindrical periphery is threaded on the pump shaft and recessed within the pump shaft coupling part, to suspend the shaft from the pump shaft coupling part. The full weight of the pump shaft, coupling and impeller, including the hydraulic thrust, is borne by the threaded connection between the pump shaft and the coupling nut. The coupling nut is tightened by a spanner wrench having projections fitting into drilled holes in the coupling nut. The pump shaft coupling part has a cylindrical inner periphery and an odd number of half holes opening to the periphery thereof. The nut has an even number of half holes opening to its periphery and so arranged that an aligned number of half holes may be formed by 1/72 of a revolution of one part relative to the other. A locking pin fits in the aligned holes and is of sufficient diameter to take the full torque load on the pump shaft and serves as a locking pin rather than a shear pin. The locking pin has a threaded hole in one end and can be removed by the insertion of a puller bolt in the threaded hole.</p> |
