GB804006A - Improvements relating to gyroscope apparatus - Google Patents

Abstract

804,006. Gyroscopic apparatus. FERRANTI, Ltd. Feb. 25, 1957 [Dec. 14, 1955], No. 35833/55. Class 97(3) [Also in Group XXXVIII] In a gyroscopic apparatus, the rotor is carried in a pair of gimbals, and means are provided for causing each gimbal bearing to oscillate about the gimbal axis and for simultaneously causing the gimbal system as a whole to rotate through at least 360 degrees about a predetermined datum axis of the framework of the apparatus. As shown in Fig. 1, the rotor 13 spins in a gimbal 12, which carries a rotor shield 12<SP>1</SP> and is journalled on ball-bearings 14 in an outer gimbal ring 15. The ring 15 is mounted for rotation about an axis 16 on ball-bearings 17 in a U-shaped bracket 21, which is pivoted about an axis 33 in a ball-bearing 22 on a second bracket 24, which in turn is mounted on the frame 10 of the apparatus to rotate about an axis 34. Axis 34 is the datum axis with which the spin axis of rotor 13 coincides, and makes an angle between 3 and 20 degrees, say 10 degrees, with the axis 33. Bracket 21 has a toothed ring 35 engaging a toothed annulus 36 mounted in frame 10, and is supported by rollers 41 mounted on bracket 24. Bracket 24 has rollers 42 running on the upper surface of annulus 36, and has a toothed ring 32 driven by a pinion 27. The rotation of the brackets gives the gimbal bearings an oscillatory motion, compounded with a rotation of the whole system about axis 34. A capacity pickoff consists of a disc 45 fixed to gimbal 12 and co-operating with four fixed condenser plates 47, whereby deviation of the spin axis from the axis 34 gives rise to an electrical signal. To apply torques to the gyroscope, double bar magnets 51, with alternate poles are mounted on disc 45 in the field of four coils 52. The rotor driving motor may be electrically supplied from slip rings, not shown. In an alternative arrangement, Fig. 2, the rotor is driven by a hysteresis motor consisting of a hard magnetic shaft 61, which carries the rotor wheels 65, 66, and stator windings 62. Shaft 61 is carried by ball-bearings 63 in a frame 64, which constitutes the inner gimbal and is mounted in ball-bearings in an outer gimbal 71, which in turn is journalled in a ring-shaped bracket 74. The bracket 74 is journalled in a U-shaped bracket 77 about an axis 75, which is at 45 degrees to the gimbal axes. Bracket 77 is supported for rotation about the datum axis 78 of the apparatus by rollers 81 running on a track 82 at the base of the apparatus casing 80. An electric motor 83, mounted on bracket 77, drives through reduction gearing a pinion 86 engaging a spur wheel 87 on the base of casing 80, so as to rotate bracket 77 and the parts carried thereby. Motor 83 also drives a disc 88 carrying a pin 89 which engages a slot 90 formed in the end of an arm 92 connected to bracket 74, causing a rocking motion to be transmitted to the gimbal bearings. Electrical connections to the motor 83 and to the gyroscope driving motor are made through slip-rings 93 and flexible metal ligaments 95. Pick-offs consist of coils 101, 102 mounted on the frame 64 and co-operating respectively with a pair of diametrically opposite magnets 105, and a second pair of magnets at right-angles to the first. Torques may be applied to the gyro by coils 111, 112, mounted on frame 64, energized through sliprings 93 and ligaments 95, and co-operating with permanent magnets 114 mounted on casing 80. Bracket 77, or bracket 74, in Fig. 2, may be rotated continuously, or in opposite direction for an integral number of revolutions.