GB482215A - Improvements relating to gyroscopic compasses - Google Patents

Abstract

482,215. Bearings. SPERRY GYROSCOPE CO., Inc. Sept. 29, 1936, No. 26421. Convention date, Oct. 3, 1935. [Class 12 (i)] [Also in Group XX] The sensitive element of a gyroscopic compass is mounted with freedom about its vertical axis by means of an air-film thrust bearing at one end of the axis and an air-film guide bearing at the other end. An alternative ball bearing may be automatically brought into action upon failure of the air supply to the airfilm bearings. As shown, the rotor casing 1 pivots in neutral equilibrium about a horizontal axis in a vertical ring 4. The 'latter is mounted for rotation about a vertical axis in a gimbal mounted main frame 5, 51, by a lower air-film thrust bearing 6, which bears the main weight of the casing 1 and ring 4, and an upper air-film guide bearing 34. Air under pressure is supplied by a pump to an annular channel in a block 8, fixed to the frame 51, and passes between a cup 7 in the block 8 and a button 9 carried by the ring 4 to form the lower airfilm bearing. The upper bearing comprises a ball 34 on a stem 28 fixed to the ring 4 and a complementary spherical cavity in a sleeve 32 fixed to the frame 5. Air is supplied to the bearing through pipe 10<1> and a series of radial passages 37 in the sleeve 32. The alternative ball bearing, which is automatically brought into action upon failure of the air supply, is formed by a ball 25 on the top of a screw 24. The latter is normally slightly withdrawn but may be screwed into operative position by gearing driven by springs, which are normally held compressed by capsules maintained distended by the pressure of the air supply.