What is the working principle of the axial displacement indicator of the air compressor?

The common axial displacement indicators of air compressor are electromagnetic type and hydraulic type. Electromagnetic axial displacement indicator consists of three parts, namely, the sender, the relay and the indicator table. The working principle of the sender is shown in Figure 135. The flange of the compressor rotor is located in the "mountain" shape iron core, and the coil of the middle iron core is provided with alternating current by the regulated power source. When the rotor is in displacement, the distance between the rotor flange and the left and right parts of the iron core will change, and the size of the inductive potential generated in the coils on both sides is different. The size of the axial displacement can be read through the relay and the indicating instrument.
According to the working principle of hydraulic axial displacement indicator, it consists of the nozzle and the flange on the rotor shaft to form the nozzle baffle mechanism. Adjust the oil inlet pressure to about 0.6MPa. When axial displacement occurs and clearance △s changes, the back pressure of the nozzle will change accordingly. According to the change of output pressure P, the size of axial displacement can be indicated, and at the same time, it can be connected to the electric contact pressure gauge to alarm.