| 摘要 |
1,240,052. Gyroscopic stabilizers. TETRA TECH Inc. and SANTA FE INTERNATIONAL CORP. Jan.29, 1969 [Feb.19, 1968], No.4998/69. Heading G1C. Apparatus for stabilizing a body against oscillatary angular displacement about an axis 2 e.g. a ship in roll, comprises a gimbal 7 supported for rotation relative to the ship about the athwartships axis 3, a rotor 13 mounted to spin in the gimbal 7 about an axis 17 perpendicular to the axis 3, and hydraulic springs 18, 19 for applying a restoring torque to the gimbal 7 about the axis 3, the restoring torque varying as a non-linear function of the angular displacement of the gimbal about the axis 3 from the position in which the axes 17 and 2 are orthogonal the non-linearity being controlled by varying the restoring characteristics of the springs 18, 19 as a function of the sensed roll frequency of the ship about the axis 2. It has been found that by using a measurement of the roll frequency of the ship to control the restoring characteristics of the springs 18, 19 in a manner the theory of which is given in the Specification, particularly effective stabilization will result. Means are also provided for increasing the rate of change restoring torque as a function of angular displacement of the gimbal 7 from the position in which the axes 17, and 2 are orthoganal and for providing different restoring characteristics for the hydraulic springs for relatively small and large displacements of the gimbal 7 about the axes 3. The springs 17, 18 are preferably oil filled hydraulic springs with an air-space the volume of which is variable by pumping in or out oil so as to vary the spring characteristics. A brake 30 is also provided to reduce the angular velocity of the rotor. The above described arrangements take no account of movements of the ship in pitch about the axis 3 and the effect these movements will be to either under- or over-compensate for the effects of roll depending on the direction of rotation of the rotor 13 and the direction of movement of the ship about the pitch axis 3. This is overcome by providing two identical stabilizers of the type described above but disposed so that their rotors rotate in opposite directions. |
