Super-precision ball bearings for gyroscopes (1) Bearings for gyroscopes and gyroscopes Bearings, other special shape bearings, examples of applicable conditions 12 000, 24 000 min-1 or 36 000 min-160 ～ 80 °C in helium gas ± 2 °C swing normal temperature～80 °C silicone oil or input shaft gyroscope in the atmosphere Rotor gimbal output shaft gimbal support bearing rotor support bearing rotating shaft (H) spring or torque meter shock absorber Figure 2 Type of gyroscope 1 degree of freedom gyroscope rotor support bearing gimbal gimbal support bearing 2 free Degree gyroscope■ Special-purpose ball bearings are used to detect the navigation azimuth and angular velocity of aircraft, ships, etc. The gyroscope is divided into 1 degree of freedom and 2 degree of freedom in structure according to the detected movement direction, speed, etc. (see figure 2). Since the characteristics of the bearings used greatly affect the performance of the gyroscope, it is required to select the best quality ultra-precision miniature bearings. The bearings supporting the high-speed rotor shaft and the outer frame (gimbal) should have stable low friction torque. The main types and applicable conditions of special rolling bearings for gyroscopes are shown in Table 11. The rotor and gimbal support bearings are mainly British super-precision bearings. The main dimensions and representative models are shown in Table 12 (page B75). In addition, there are many special-shaped gyroscope bearings. (2) Characteristics of gyroscope bearings Special bearings for rotors and special bearings for gimbals Special bearings for drip rotors require extremely low torque and long-term stability during high-speed rotation. Therefore, oil-containing cages are often used. There is also a lubrication method in which solvent-melted lubricating oil is injected into the bearing, but because the friction torque is affected by the amount of oil, it is necessary to adjust the appropriate concentration (see Figure 3). The centrifugal separation method can be used to adjust the oil volume to obtain a stable torque. As for the bearing type, there are also special-shaped bearings in which the end cover and the outer ring are integrated (see Figure 4). The special bearing for the gimbal serves as the output shaft and must have low friction torque and vibration resistance. Table 13 lists the maximum starting torque of representative bearings. Through the special design of raceway finishing and cage, lower starting torque can be obtained. In addition, in order to prevent fretting wear caused by external vibration, the raceway is hardened with a surface coating to improve vibration resistance. The design parameters of special bearings for rotors and gimbal frames are shown in Table 14.