Abstract: A rotor assembly includes a rotor assembly housing, a shaft, a bearing assembly coupling the shaft to the rotor assembly housing, and a mass structure coupled to and rotatable with the shaft. The bearing assembly includes a bearing housing, a first raceway defined in the bearing housing, a second raceway defined in the shaft, and a plurality of ball bearings positioned within the first and second raceways to enable the shaft to rotate relative to the rotor assembly housing.

Abstract: A valve is provided for use on a control moment gyroscope (CMG) having a housing separating an internal environment from an external environment. The valve includes a valve housing, a valve element, and bellows. The valve housing is configured to couple to the CMG housing and includes an inner surface defining a cavity, an outer surface, and an opening extending therebetween. The valve element is disposed within the valve housing cavity and is movable between a closed position, in which fluid is prevented from flowing through the valve housing opening, and an open position, in which fluid may flow through the valve housing opening. The bellows is disposed within the valve housing and coupled to the valve element and has an internal chamber. The bellows selectively moves the valve element closed and open in response to a differential pressure between the bellows internal chamber and the valve housing cavity.

Abstract: A lubrication medium supply system and method for delivering lubricant to, for example, the spin bearings of a control moment gyro (CMG), includes a reservoir, a motor, and a valve. A lubrication medium is placed within the reservoir, and the motor, which is coupled to the reservoir, compresses, and thereby pressurizes, the lubrication medium. The valve opens in response to the pressurization of the lubrication medium, to thereby dispense a predetermined amount of lubrication medium from the reservoir, while simultaneously depressurizing the lubrication medium in the reservoir.

Abstract: A lubrication medium supply system and method for delivering lubricant to, for example, the spin bearings of a control moment gyro (CMG), includes a reservoir, a motor, and a valve. A lubrication medium is placed within the reservoir, and the motor, which is coupled to the reservoir, compresses, and thereby pressurizes, the lubrication medium. The valve opens in response to the pressurization of the lubrication medium, to thereby dispense a predetermined amount of lubrication medium from the reservoir, while simultaneously depressurizing the lubrication medium in the reservoir.

Abstract: A method and apparatus for measuring vibrational forces emitted by a reaction wheel assembly during rotation of its rotor includes a low mass carriage (12) supported on a large mass base (10). The carriage (12) is in the form of an octagonal frame having an opening which is adapted for receiving the reaction wheel assembly (W) supported thereon by means of a mounting ring (22). The carriage (12) is supported on the base (10) by means of air bearings (A) which support the carriage in a generally frictionless manner when supplied with compressed air from a source (50). A plurality of carriage brackets (34) and a plurality of base blocks (30) provide for physical coupling of the base (10) and carriage (12). The sensing axes of the load cells (B) are arranged generally parallel to the base (10) and connected between the base and carriage such that all of the vibrational forces emitted by the reaction wheel assembly (W) are effectively transmitted through the sensing axes of the load cells.