The DWQZ - Φ 11 eddy current displacement sensor produced by Liuhe Measurement and Control can monitor and analyze faults in rotating machinery, and detect problems in a timely manner. These problems include synchronous vibration of the shaft, loose sleeve of the shaft, bearing failure of rolling components, wear of Babbitt alloy of bearings, shaft bending, uneven air gap of electric motors, resonance of turbine blade channels, loosening of oil film instability components, compressor kick vibration, misalignment of the shaft inside the casing, rotor imbalance, excessive bearing gap, axial/Radial, coupling "locking", shaft cracks, and gear meshing issues. Eddy current displacement vibration sensors are used for steam engines, gas turbines, and compressors. Measurement of vibration, displacement, and wear of turbomachinery, generator sets, various centrifugal machinery, and reciprocating machinery.zuiThe two commonly used types of eddy current displacement sensors are ф8mmAnd ф1lmmProbe. Due to their small structural size and ample linear range, they can directly measure the rotating surface. The specific measurement items include:

1Radial vibration of the shaft

By installing sensors at the radial position of the shaft, mechanical faults such as rotor misalignment and imbalance can be detected, and the working status of the bearings can be indicated (usually using a probe with a diameter of φ)8Sensors).

2Measurement of axial displacement

For rotating machinery, excessive axial displacement can cause significant damage to the mechanism. The measurement of axial displacement can indicate the axial clearance or relative instantaneous displacement change between rotating and fixed components,To prevent damage to the machine, axial displacement refers to the gap between the internal rotor of the machine along the axis direction relative to the thrust bearing. It can measure its axial displacement, wear or potential bearing failure of the thrust bearing, wear and failure of the balance piston, looseness of the thrust flange, locking of the coupling, etc. (usually using a diameter of φ)11Sensors).

3Key phase measurement(See figure)

Keyphase measurement is achieved by setting a groove or convex groove on the measured axis, known as a keyphase marker. When this groove or convex groove is rotated to the position of the probe, it is equivalent to a sudden change in the distance between the probe and the measured axis. In this way, the sensor will generate a pulse signal, and every revolution of the measured axis will generate a pulse signal, indicating the position of the axis in each revolution cycle.

Therefore, by counting the pulses, the rotational speed of the shaft can be measured, and by comparing the pulses with the vibration signal of the shaft, it can be determined

The phase angle of vibration can be used for dynamic balance analysis of shafts and fault analysis and diagnosis of equipment.

4Eccentricity measurement:

Eccentricity is a measurement of the degree of shaft bending at low speeds, which can be caused by the following conditions: original mechanical bending, bending caused by temporary temperature rise, and gravity bending in a stationary state.

The measurement of eccentricity is crucial for evaluating the overall mechanical condition of rotating machinery. Especially for turbomachinery, eccentricity measurement has become an indispensable measurement item during start-up or shutdown, allowing you to see the amplitude of shaft bending caused by heating or gravity. The eccentric position of the rotor, also known as the radial position of the shaft, is often used to indicate bearing wear and the magnitude of the load. It is also used to determine the azimuth angle of the shaft, which can indicate whether the rotor is stable.

5Differential expansion measurement

For steam turbine generator sets, during the start-up and shutdown process, due to the different metal materials, the heat dissipation and thermal expansion coefficients are also different. The thermal expansion of the shaft may exceed that of the shell, which may cause the rotating and stationary parts of the turbine machinery (such as the shell, nozzle, pedestal, etc.) to come into contact with each other, which may lead to damage to the machine. Therefore, it can be seen that measuring the differential expansion is very important (usually using a diameter of )25Sensors).

6Speed measurement

For all rotating machinery, it is necessary to monitor the shaft speed, which is an important indicator for measuring the normal operation of the machine. The advantage of using eddy current sensors to measure rotational speed is incomparable to any other sensor. It can respond to both zero and high rotational speeds, and has strong anti-interference performance. The above three types of probes can withstand the harsh environment encountered inside the steam turbine.

4、 Other uses:

Measure the upward movement of the combustion nozzle shaped valve in a diesel engine;

Measure the movement of the piston inside the cylinder;

Monitor the pressure of the rolling mill;

Detect the deflection of cars, bicycles, and motorcycles;

Detect the dynamic balance of the electric fan shaft and blades;

Monitor the vibration of fuel rods in atomic reactors;

Measure the vibration of various parts of the ship's propeller;

Measure the deformation of the press under high pressure;

Measure the thermal expansion of steam pipes;

Determine the wear and tear of high-speed motors;

Measure the movement of the braking object;

Measure experimental models of buildings, bridges, vehicles, airplanes, dams, etc

Displacement type deformation during vibration, centrifugation, and static tests;

Measure the displacement or deformation of mechanical components relative to zero position when subjected to force;

Monitor the vibration of precision machine tools;

Precise positioning during the installation of workpieces on large grinding machines;

Detect the dimensional tolerances of workpieces in the assembly line and automatically count them;

Measure the rotational speed;

Online detection of dimensional tolerances of tubes and bars during cold rolling process;

Measurement and positioning of maglev trains;

Positioning and measurement of magnetic levitation equipment;

Detect the curvature of the welded joint of the long rolled steel;

Detect the inner and outer diameters of the workpiece;

Detect the thickness of insulation materials for heating equipment;

Detecting the thickness of non-metallic coatings on metal surfaces:

Measure the vibration of high-speed rotating spindles in textile machinery;

Vibration resistance tests for automobiles, airplanes, and tanks;

Identification of currency authenticity:

Combining new pressure, speed, flow and other sensors.