Control moment gyroscopes (CMGs) are commonly employed in satellite attitude control systems. A generalized CMG may include a main CMG housing and an inner gimbal assembly (IGA), which is mounted within the main CMG housing for rotation about a gimbal axis. The IGA includes, amongst other components, a rotor assembly, at least one spin motor, and a rotor support structure. In one known design commonly referred to as a “shell rotor architecture” or, more simply, a “shell rotor,” the rotor assembly includes an annular rotor rim disposed between first and second hemi-spherical rotor shell pieces. The rotor rim is welded to the first and second rotor shell pieces along first and second circumferential rim-shell weld joints, respectively. Collectively, the rotor rim, the first rotor shell piece, and the second rotor shell piece form a generally spherical body having a central channel through which a rotor shaft extends. During operation, the spin motor rotates the rotor assembly about a spin axis at a relatively high rate of speed. The IGA is, in turn, selectively rotated about the gimbal axis, which is generally perpendicular to the rotor spin axis, by an actuator (e.g., a torque module assembly) mounted within the main CMG housing. When the IGA is “gimbaled” in this manner, a controlled torque is generated about an output axis normal to the spin and gimbal axes due to momentum transfer of the rotor assembly. This gyroscopic torque is imparted to the host satellite through a CMG mount interface, such as an annular flange bolted to the exterior of the satellite. By selectively rotating the IGA about the gimbal axis, the satellite's attitude may be adjusted and re-adjusted, as needed, in a highly controlled manner.
CMG shell rotors of the type described above have been developed and commercially implemented with considerable success by the assignee of the present Application, Honeywell International Inc. In general, CMG shell rotors provide superior performance characteristics as compared to other conventionally-known CMG rotors, including superior momentum-per-weight ratios and relatively high operational speed limits, as well as high angular stiffness. However, further improvements in momentum-per-weight ratios, speed capabilities, and other measures of CMG performance (e.g., operational lifespan) are still desirable. Moreover, as a notable disadvantage, the manufacturing schedule and costs associated with manufacture of CMGs having shell rotor-based architectures tend to be substantial. It is not uncommon for commercial production of a shell rotor to cost upwards of several hundred thousand U.S. dollars and to require over one year to complete.
It is thus desirable to provide CMGs including advanced rotors having improved performance characteristics (e.g., increased momentum-per-weight ratios, higher speed limits, longer operational lifespans, and so on) as compared to shell rotor assemblies and other conventionally-known CMG rotor assemblies. Ideally, embodiments of such a CMG, and specifically embodiments of the advanced rotor included within the CMG, would be amenable to production utilizing cost effective and time efficient manufacturing processes. It would also be desirable to provide manufacturing processes for producing CMGs including such high performance rotors. Other desirable features and characteristics of the present invention will become apparent from the subsequent Detailed Description and the appended claims, taken in conjunction with the accompanying drawings and this Background.