| 摘要 |
1481839 Vibration damping DEFENCE SECRETARY OF STATE FOR 11 Feb 1975 [14 Feb 1974] 6804/74 Heading F2S [Also in Division G1] A dynamically tuned gyroscope for an aircraft inertial guidance system comprises a drive shaft 14 connected to a gimbal 12 by a first torsion flexure 13, and a rotor 10 connected to the gimbal 12 by a second torsion flexure 11, the first and second torsion flexures 13, 11 being orthogonal, the effective torsional stiffness of the first flexure 13 being zero whilst that for the second flexure 11 equals 4w<SP>2</SP>r<SP>2</SP>m where w is the tuned rotational speed, m the component mass of the gimbal 12 on an axis through its centre of gravity and normal to its plane, and r is the distance of mass m from the centre of gravity of the gimbal. Mathematic argument given shows that such values for the effective torsional stiffnesses results in a system which is not sensitive to angular vibration at twice the rotational frequency. The torsional stiffness of the first flexure 13 may be made zero by over centre or toggle spring action, or by adding a magnetic or electrostatic system below the gimbal. |
