Abstract: A rigid coupling, suitable for turbomachines, includes friction flanges for transferring torque from one shaft to another, bolts for axially coupling the friction flanges together, and shearing bushings which encompass these bolts and which prevent relative radial motion between the flanges. One-half of the outer sidewall surface of each such shearing bushing is cylindrical, while the other half of the outer sidewall surface is conical. The cylindrical half of each shearing bushing is larger than the bore which accommodates it in one of the flanges, and is inserted by means of a shrink fit. The conical half of the shearing bushing mates with a bore in the other flange which has the same conical shape. Each shearing bushing may also have grooves cut into its frontal surfaces to form collars which flex during use.

Abstract: A valve spindle drive is disclosed in which the travel of the spindle is limited by a locking mechanism. The spindle is driven by a gearing system on which locking rings are provided. Each locking ring permits rotation in one direction. Arms resiliently mounted on the valve housing carry a second pair of locking rings for mating with the rings on the gearing system. Deflection of the arms during travel of the spindle actuates switches for controlling a spindle motor drive. Movement of the spindle and gearing relative to the second pair of locking elements provides for engagement of a pair of respective locking rings to prevent further spindle travel. The other pair of rings is prevented from coupling by a cam device carried by the gearing.

Abstract: Apparatus provided for testing the shaft/bearing insulation characteristic of a rotary machine, e.g., a turbo-machine, wherein the shaft is normally earthed by means of an earthing brush on the shaft and connected to ground. A first circuit arrangement is provided for breaking the shaft-earthing connection, a second circuit arrangement is provided for applying an increasing test voltage between the shaft bearing which is grounded and the earthing brush while the shaft-earthing connection remains broken, this being in the form of a progressively charged capacitor connected between the shaft bearing and earthing brush, and a third circuit arrangement is provided for measuring the change in voltage across the capacitor resulting from a breakdown in the insulation between the shaft and its bearing during the testing operation.