System and method for measuring an axial position of a rotating component

An aircraft engine comprising:

• a bladed rotor rotatable about a rotation axis and having pitch-adjustable blades;
• a toothed ring coaxial with the rotation axis, the toothed ring including:
• an inclined tooth extending axially relative to the rotation axis and having an axially non-uniform radial height;
• and
• a reference tooth extending axially relative to the rotation axis and having an axially uniform radial height;
• an inclined sensor adjacent to the toothed ring, the toothed ring being rotatable about the rotation axis and translatable axially along the rotation axis as a function of a pitch angle of the pitch-adjustable blades, the inclined sensor being configured to generate a positioning signal indicative of a gap between the inclined tooth and the inclined sensor along a sensor axis of the inclined sensor as rotation of the toothed ring relative to the inclined sensor occurs, the sensor axis of the inclined sensor being perpendicular to a top surface of the inclined tooth;
• a reference sensor fixedly mounted relative to the inclined sensor and adjacent to the toothed ring, the reference sensor being configured to generate a reference signal indicative of a gap between the reference tooth and the reference sensor along a sensor axis of the reference sensor as rotation of the toothed ring relative to the reference sensor occurs, the sensor axis of the reference sensor being perpendicular to the rotation axis;
• and
• a computer operatively connected to the inclined sensor and to the reference sensor, the computer being configured to generate an output indicative of a relative axial position between the toothed ring and the inclined sensor based on the positioning signal and the reference signal.

A method for measuring an axial position of a phonic wheel, the method comprising:

• directing a first magnetic field from a first sensor toward a location that a first tooth of the phonic wheel is expected to occupy as the phonic wheel rotates about a rotation axis relative to the first sensor, the first tooth extending axially relative to the rotation axis and having an axially non-uniform radial height, the first sensor being inclined relative to an orientation perpendicular to the rotation axis;
• detecting a variation in the first magnetic field caused by movement of the first tooth in the first magnetic field;
• generating a first feedback signal based on the detection of the variation in the first magnetic field;
• directing a second magnetic field from a second sensor toward a location that a second tooth of the phonic wheel is expected to occupy as the phonic wheel rotates relative to the second sensor about the rotation axis, the second tooth extending axially relative to the rotation axis and having an axially uniform radial height;
• detecting a variation in the second magnetic field caused by movement of the second tooth in the second magnetic field;
• generating a second feedback signal based on the detection of the variation in the second magnetic field;
• and
• generating an output indicative of the axial position of the phonic wheel based on the first feedback signal and the second signal.