Torque-limiter health monitoring

A predictive system for a ball-ramp mechanism comprising a first plate to which an input shaft is coupled, a second plate to which an output shaft is coupled and a ball element which is disposable within complementary recesses in interior faces of the first and second plates, the predictive system comprising:

• a sensor disposed to sense a distance between the interior faces of the first and second plates in a dimension defined along a longitudinal axis of the input and output shafts;
• and
• a processing system coupled to the sensor and configured to process readings of the sensor, to calculate whether the distance between the interior faces of the first and second plates is indicative of degradation or failure incidents based on the readings being processed and to determine whether an action should be taken based on a calculation result,
• wherein the processing system calculates that the distance between the interior faces of the first and second plates is indicative of the degradation or failure incidents based on the distance between the interior faces of the first and second plates exceeding a first threshold or reaching a second threshold, respectively.

A method of operating a predictive system for a torque-limiter comprising a ball-ramp mechanism with first and second plates, the method comprising:

• sensing a distance between a sensor and an exterior face of the first plate of the ball-ramp mechanism;
• determining a condition of the torque-limiter in accordance with results of the sensing, the condition comprising a distance between interior faces of the first and second plates of the ball-ramp mechanism;
• calculating whether the condition of the torque-limiter is indicative of degradation or failure incidents, wherein the calculating comprises calculating that the distance between the interior faces of the first and second plates of the ball-ramp mechanism exceeds a first threshold without reaching a second threshold and determining that the condition is indicative of the degradation incident based on the distance between the interior faces of the first and second plates of the ball-ramp mechanism exceeding the first threshold without reaching the second threshold;
• and
• determining whether an action should be taken based on a calculation result.