An electromagnetic angle sensing structure comprises a front cover with a display module electrically connected to a control circuit with a sensing module provided with a sensing area formed by at least one sensing coil, the circuit comprises a sensing control unit generating an electromagnetic variable quantity and a central processing module receiving the variable quantity and storing an angle data; and an inner assembly body with a front side formed with a curvature guide rail, being filled with a liquid and disposed with a metal ball displacing in the guide rail, an electromagnetic field generated by the coil generates changes in an inductance value due to the ball passing through, the sensing control unit generates the variable quantity being transmitted to the central processing module, an angle information converted by the central processing module through the variable quantity and the angle data is displayed on the display module.

A compact fall detection sensor includes a case. A magnet is housed in the case. A reed switch with a pair of reeds are integrally positioned around the central axis of the case at the bottom of the case. In an upright state, the magnet is gravitationally positioned in the longitudinal direction of the reed switch around the central axis of the curved surface of the case, each magnetic pole magnetizing the corresponding reed of the reed switch, allowing one of the reeds to be magnetized to N pole and the other reed to S pole to turn on the switch. When inclined from the upright state, the magnet slides along the curved surface of the case and deviates from the central axis, to position only one of the magnetic poles of the magnet around the central axis to turn off the reed switch.

A variable inductor direction sensor may include a rotatable body having a first circumferential tooth array and a stationary body having a second circumferential tooth array. The second circumferential tooth array may be concentric with the first circumferential tooth array. The rotatable body may be disposed relative to the stationary body such that one of the first circumferential tooth array and the second circumferential tooth array circumscribes the other of the first circumferential tooth array and the second circumferential tooth array. Further, at least one of the first circumferential tooth array and the second circumferential tooth array has a non-uniform circumferential geometry.

A compact fall detection sensor includes a case. A magnet is housed in the case. A reed switch with a pair of reeds are integrally positioned around the central axis of the case at the bottom of the case. In an upright state, the magnet is gravitationally positioned in the longitudinal direction of the reed switch around the central axis of the curved surface of the case, each magnetic pole magnetizing the corresponding reed of the reed switch, allowing one of the reeds to be magnetized to N pole and the other reed to S pole to turn on the switch. When inclined from the upright state, the magnet slides along the curved surface of the case and deviates from the central axis, to position only one of the magnetic poles of the magnet around the central axis to turn off the reed switch.

A tilt sensor for signaling when the tilt sensor is not vertical. The tilt sensor includes a metallic ball that is free to move and capable of resting at a low point when the tilt sensor is vertical. A proximity sensor directed at the low point communicates when the metallic ball has deviated from its position of repose, indicating that the sensor is no longer vertical.

A variable inductor direction sensor may include a rotatable body having a first circumferential tooth array and a stationary body having a second circumferential tooth array. The second circumferential tooth array may be concentric with the first circumferential tooth array. The rotatable body may be disposed relative to the stationary body such that one of the first circumferential tooth array and the second circumferential tooth array circumscribes the other of the first circumferential tooth array and the second circumferential tooth array. Further, at least one of the first circumferential tooth array and the second circumferential tooth array has a non-uniform circumferential geometry.

A tilt sensor for signaling when the tilt sensor is not vertical. The tilt sensor includes a metallic ball that is free to move and capable of resting at a low point when the tilt sensor is vertical. A proximity sensor directed at the low point communicates when the metallic ball has deviated from its position of repose, indicating that the sensor is no longer vertical.

An aero engine rotor air floatation assembling method and device based on a gantry structure belong to mechanical assembling technology. The present invention can effectively solve the problem of poor coaxality after the aero engine rotor is assembled and has the characteristics of high coaxality after the rotor is assembled, reduced vibration, mounting easiness, high flexibility and improved engine performance. The measuring method and device are: determining rotary reference based on a rotary air bearing; determining the angular positioning of a rotary table according to a grating ruler; extracting the radial error of the radial mounting plane and the inclination error of the axial mounting plane of the rotor based on the four-probe measuring device to obtain the influencing weight of this rotor to the assembled rotor on coaxality; measuring respectively all the rotors required for assembling to obtain the influencing weight of each rotor to the assembled rotor on coaxality; vector optimizing the weight of each rotor to obtain the assembling angle of each rotor.

An aero engine rotor air floatation assembling method and device based on a gantry structure belong to mechanical assembling technology. The present invention can effectively solve the problem of poor coaxality after the aero engine rotor is assembled and has the characteristics of high coaxality after the rotor is assembled, reduced vibration, mounting easiness, high flexibility and improved engine performance. The measuring method and device are: determining rotary reference based on a rotary air bearing; determining the angular positioning of a rotary table according to a grating ruler; extracting the radial error of the radial mounting plane and the inclination error of the axial mounting plane of the rotor based on the four-probe measuring device to obtain the influencing weight of this rotor to the assembled rotor on coaxality; measuring respectively all the rotors required for assembling to obtain the influencing weight of each rotor to the assembled rotor on coaxality; vector optimizing the weight of each rotor to obtain the assembling angle of each rotor.

The invention relates to a device (100) for measuring the angular errors in the inclination of a real axis of rotation (204) of a rotary element (101), the device comprising control electronics (111) controlling the rotation of the rotary element (101) about its real axis of rotation (204), a first and a second rotation sensor (112a, 112b) for obtaining angular velocities about two measurement axes (302, 304) which are orthogonal to one another and both orthogonal to the real axis of rotation (204), a third rotation sensor (112c) making it possible to obtain the angular position and angular velocity of the rotation element (101) about its real axis of rotation (204), at least two of the aforementioned sensors being inertial sensors making it possible to obtain projections of the vector of the speed of rotation of the Earth onto at least two axes of projection, an acquisition unit (113), a measurements-storage memory (114), a computation unit (115) configured to compute, from the angular positions and velocities obtained from the aforesaid sensors, the angular errors in the inclination of the real axis of rotation (204) of the rotary element (101).