| 摘要 |
<p>847,820. Automatic speed-control systems. LIAAEN, N. J. Dec. 24, 1956 [Dec. 23, 1955], No. 39240/56. Class 38 (4). [Also in Group XXVI] A turbine driving a variable-pitch propeller has a brake associated with the turbine shaft and an electromagnetic clutch for engaging and disengaging the brake operated by means dependent upon variations in the number of revolutions or in the turbine load. A fluid-filled hydraulic brake 11 is connected to the shaft of the turbine 3 through an electromagnetic clutch 12 engaged and disengaged by a contactor 13. The contactor 13 is operated by a switch 18 controlled by a torque meter 19. The torque meter 19 comprises a U-shaped iron core magnetized by an alternating current, the poles of which are located a few millimetres away from the surface of the turbine shaft. At right angles to this core and combining to form a measuring head is a similar U-shaped iron core which is also equipped with a winding. A variation in the load or stress condition of the shaft affects the balance between the two fluxes produced by the two magnets thereby deviating the direction of the combined fluxes, which deviations are utilized for measuring or actuating purposes. In a modification, the contactor 13 is actuated by a speed governor. The hydraulic brake may be replaced by an electromagnetic or electrodynamic brake.</p> |
