The gap between the stator and the rotor is called the air gap of the motor. If the air gap is too large, the magnetic resistance increases and the excitation current increases, resulting in a decrease in the power factor of the motor. However, the air gap cannot be too small. If it is too small, the stator and rotor may rub against each other, commonly known as chamber sweeping. Bore sweeping is generally due to bearing wear, rotor sinking or shaft deflection is too large due to rotor eccentricity. If the rotor is simply made smaller, the air gap between the stator and the rotor will be increased, and the excitation current will increase, which will deteriorate the operating performance of the motor and reduce the efficiency and power factor. For the motor, smooth operation can lead to longer working time. Especially for large motors, unstable operation can lead to fatal damage and huge property losses. The high-precision capacitive displacement sensor provided by the German company Iridium can reliably measure the concentricity of motor rotation when the motor is running.
Large motors are often used for ore crushing or mining in the cement industry. Precision sensors are used to monitor whether the rotor of the motor is running smoothly in the stator. If the motor runs out of balance, the rotor may come into contact with the stator, causing damage to the motor.
The capacitive displacement sensor provided by the German company Iridium can be used for non-contact detection of distance and displacement. In large motors, sensors are used to detect the gap between the motor rotor and stator. For this application, a capacitive displacement sensor with a measuring range of 30mm is generally selected.
Measuring tasks in electric motors face many challenges, and the capaNCDT6220 range of capacitive displacement sensors from the German company Miridium ensures reliable detection. There is usually a magnetic field in the motor, and the capacitive sensor can be protected from the influence of the magnetic field. In small installation spaces, flat capacitive probes with a height of only 2.5mm can be used. Cable length is also a huge problem, large motor huge size requirements sensor cable can reach more than 8m. Typically, a large motor needs to be measured with an 8-channel or even 16-channel sensor. Permanent mechanical modification of the motor is not necessary, and the measurement uses the non-contact measurement principle, thus ensuring long-term stability and reliability.
Accuracy, stability, resolution and scanning frequency are important parameters of capacitive sensors. Sensors are widely used to measure the motion and tolerance of workpieces, and how to realize process control. The measured parameters have many forms: vibration, amplitude, gap, position, inclination, flatness, contour, deformation, travel, roundness, thickness, displacement and shape.