The speed sensor is generally used to measure the vibration of the bearing, and in a few cases will also be used to measure the vibration of the rotating shaft. When measuring the vibration of the rotating shaft, the installation of the speed sensor is relatively simple. At present, there are four methods used in the field: hand-held, plastic clay sticky water magnetic chuck fixation, bolt fixation and so on. In temporary vibration measurement, most of them use hand-held sensors. This method is flexible and easy to use, especially when the number of vibration sensors is insufficient and the interchangeability of the sensors is not good. It has outstanding advantages; but the test error is relatively Large, and labor intensity is also great. It is more convenient to stick the sensor with plasticine. The accuracy of the measurement is much higher than that of the handheld. The top of the bearing base vibrates vertically, horizontally and axially. When the bonding is firm and the frequency is 50 Hz, the maximum energy of this method is 300 μm. The main disadvantage of the plasticine adhesive sensor is that its adhesive force is greatly affected by temperature. Higher and lower temperatures will significantly reduce the adhesive force, so it is not suitable for high temperature and high pressure rotors and disc wheels of higher temperature steam turbines. Bearings; when the cold start in winter, the bearing temperature is too low to use. It is more convenient to fix the sensor by the permanent magnet chuck than the plasticine. At present, the permanent magnet chuck with the size of φ50 or 50mm * 50mm can also be manufactured in China. Adsorbed on the horizontal surface, the maximum measurement of 1000μm vibration. However, the bearing seat of the general unit is coated with mud and paint, which reduces the suction of the suction cup. Therefore, when it is adsorbed on the vertical plane and the amplitude is large, the handrail is still needed to avoid falling off and breaking the vibration sensor. Fixing the sensor directly on the bearing with bolts can not only reliably measure the vibration in three directions on the top of the bearing housing, but also measure the vibration in two directions on the vertical plane. This installation method is the strongest of the four installation methods. In order to obtain correct measurement results, the installation of the speed sensor should pay attention to: (1) Operating temperature Generally, the working temperature of the speed sensor is below 120 degrees. Excessive temperature will damage the vibration sensor's insulation and demagnetize, reducing its sensitivity. For the bearings of high and medium pressure rotors, when the leakage of the shaft seal is serious, the sensor cannot be installed on the bearing for a long time. (2) Avoid unstable vibration sensor and resonance No matter which way is used to connect with the bearing, the sensor must be tightly fixed on the measured object, and there must be no looseness, otherwise it will cause impact of the sensor and make the measurement result inaccurate. The sensor is fixed with a single bolt, which sometimes causes the resonance of the sensor, which is the obvious lateral vibration of the sensor. Cause measurement errors. In order to avoid the resonance of the sensor, the connecting bolt should not be smaller than M8, and the contact surface between the sensor and the measured object must be flat, and the diameter of the contact surface should not be smaller than 20mm. If an external tool is used to fix the sensor on the bearing, the height of the tool should be reduced as much as possible, otherwise the measured vibration will be amplified. (3) The position of the measuring point must be consistent before and after The bearings of general equipment have large differences in vibration at different positions. Therefore, where the vibration sensor is fixed by hand-held, plasticine bonding and water magnetic chuck, the position of the measurement point should be marked to avoid the difference between the front and rear measurement points. An error has occurred. This is especially important for vibration fault diagnosis and vibration measurement in rotor balancing. (4) Interchangeability of vibration sensors In order to reduce the labor intensity of the test, several to dozens of sensor measurement points are currently used in the unit vibration test. For the same point of vibration, when different vibration sensors are used for measurement, the sensitivity and phase characteristics of each sensor should be unified, and only those that have undergone rigorous testing can be interchanged in the test, otherwise it will cause larger measurement errors. In order to avoid measurement errors caused by poor interchangeability of the sensor, the sensor should be seated (measuring point). However, the measurement results can only be compared longitudinally (front-to-back). For horizontal comparison, it is best to use the same sensor to measure the vibration at each point. (5) The installation direction of the vibration sensor should be consistent with the required measurement direction Bearing vibration is often particularly noticeable in a certain direction. When the sensor direction deviates slightly from the measurement direction, the indicator value of the instrument will change greatly, especially when the handheld sensor is used, because the rubber temperature softens when the bearing temperature increases, The sensor is tilted and deviates from the measurement direction. Therefore, you should always pay attention to the installation direction of the sensor when measuring vibration. Stainless Leveler Feet,Stainless Adjustable Feet,Stainless Leveling Feet,Stainless Steel Adjustable Leveling Feet Cixi Ruixin Machine Components Co., Ltd , https://www.rmlevelingfeet.com