Abstract: A valve assembly controller is configured with a table having a set of command signal values representing commanded positions of a valve element to obtain a desired flow rates through a fluid pathway. The table also includes a set of empirically measured drive signal values representing the actual positions of the valve element required to obtain the desired flow rates through the fluid pathway. During operation, in order to obtain a desired flow rate through the fluid pathway, the controller intercepts a command signal from a command signal source and provides the valve assembly with a corresponding drive signal based upon the table values. The controller therefore controls the positioning of the valve element such that the valve element is opened to a position either greater or less than the commanded position in order to provide the desired flow through the fluid pathway.

Abstract: A snap ring having improved retention characteristics is configured for use inside a cylindrical cavity. The cavity includes a retention device having a retention surface forming an obtuse angle with the cavity wall. As an axial load is applied to the snap ring, it moves along the retention surface, thereby experiencing a reduction in diameter. The snap ring includes a circumferential discontinuity defined by two generally radial planar surfaces, or ring ends. The discontinuity is configured such that the ring ends will abut one another before the snap ring diameter is reduced beyond the retaining diameter.

Abstract: Aspects of the present invention are directed to systems, methods, and computer-readable media for measuring certain actuator system parameters of an actuator, e.g., an EMA in its working environment. Stiction and backlash are examples of such parameters, and these indicate the impending failure of an actuator system than conventional approaches of measuring the elapsed time of operation. When the measured backlash and/or stiction parameters exhibit a deleterious increase over time, e.g., by exceeding a preset threshold, imminent failure or the need for service/repair of the system is indicated.

Abstract: An improved technique of acceptance testing an actuator system involves measuring system parameters of the actuator system during operation of the actuator system, and storing the measured system parameters in computerized memory as a set of measured system parameters. The technique further involves obtaining a set of predetermined thresholds. Each predetermined threshold corresponds to a particular measured system parameter. The technique further involves electronically indicating whether the actuator system is in acceptable condition based on an electronic comparison of the set of measured system parameters stored in the computerized memory and the set of predetermined thresholds, e.g., providing a warning of a need for service or of imminent failure when one or more of the system parameters exceeds a corresponding threshold.

Abstract: A snap ring having improved retention characteristics is configured for use inside a cylindrical cavity. The cavity includes a retention device having a retention surface forming an obtuse angle with the cavity wall. As an axial load is applied to the snap ring, it moves along the retention surface, thereby experiencing a reduction in diameter. The snap ring includes a circumferential discontinuity defined by two generally radial planar surfaces, or ring ends. The discontinuity is configured such that the ring ends will abut one another before the snap ring diameter is reduced beyond the retaining diameter.