SU962758A1 - Method of determining deflection of rotating shaft - Google Patents

Description

(B) METHOD FOR DETERMINING THE FLEXIBLE SHEAR

The invention relates to a measurement technique and can be used in determining the deflections of ara shafts resulting from their imbalance. A method for determining the deflection of a rotating shaft is known, which consists in the fact that the surface is cylindrical. A non-contact gap meter, made in the form of an ultrasonic interferometer, is installed in the shaft section, the variable component of its output signal is extracted, and the shaft deflection 1 is judged from its amplitude. However, the method is complicated in hardware implementation and does not provide a high accuracy of measurements due to the low level of the signal at the input of the interferometer. The closest to the proposed; 4y to the technical essence and the achieved effect is a method for determining the deflection shaft, which means that a non-contacting capacitive displacement sensor is installed on the surface of the cylindrical shaft section, the variable component of the sensor signal is separated, and its amplitude determines the deflection 2. However, the method does not provide high accuracy of measurements, since the capacitive sensor has low noise immunity and high sensitivity to vibrations. The purpose of the invention is to increase the deflection deflection. The goal is achieved in that according to the method of determining the deflection of a rotating shaft, which means that a non-contact sensor is installed at the surface of the cylindrical section of the shaft, the variable component of the signal is distinguished by its amplitude, the additional sensor is diametrically opposite

BASIC, each sensor measures the pressure of the external environment in the area of the rotating surface, inverts the power of one of the sensors, adds it to the signal of the second sensor, and extracts the variable component of the total signal.

The drawing shows a diagram of the device that implements the proposed method.

The device contains sensors 2 and 3 of the external pressure installed on opposite sides of the monitored shaft 1, made structurally in the form of elastic cantilever beams with strain gauge transducers pasted on them, amplifiers k and S of sensor signals, an inverter 6 connected to the output of the amplifier 5, adder 7, the inputs of which are connected to the outputs of the inverter 6 and the amplifier, and a block 8 for extracting a variable component of the sum signal.

The method is described as follows.

When the shaft 1 rotates in the area of the cylindrical surface, the external gas medium, for example air, is carried by the moving shaft into the gaps between V and pressure sensors 2 and 3, as a result of which the elastic beams of the sensors bend more strongly, the smaller the gap and the more linear circumferential rotation speed. When there is a deflection of the shaft 1, the gaps of the sensor 2 and sensor 3 vary in magnitude with the frequency of rotation of shaft 1. The signals of sensors 2 and 3 are out of phase by 180, and inverter 6 compensates for this phase shift, and adder 7 allows to obtain double amplitude ... signaled The variable selection block 8 consists of a total signal.

variable and constant components. The variable component carries information about the amount of deflection of the shaft, and constant - about the speed of rotation of the shaft. The proposed method makes it possible to determine with sufficient accuracy the deflections in a wide range of amplitudes. The implementation of the method requires simple equipment, the maintenance of which does not require high qualifications, and the high signal power level at the sensor input reduces the effect of destabilizing factors on the output signal of the device.

invention formula

The method for determining the deflection of a rotating shaft, which consists in installing a contactless sensor near the surface of the cylindrical shaft section, isolating the variable component of the signal and determining the deflection by its amplitude, characterized in that, in order to improve the deflection determination accuracy, an additional sensor is installed diametrically opposite to the main one, each sensor measures the pressure of the external environment in the area of the rotating surface, inverts the signal of one of the sensors, folds it with the signal of the second sensor and extract the variable component of the sum signal.

Sources of information taken into account in the examination

1. USSR Author's Certificate No. 390397, cl. G 01 M 1/22, 1U71.

2. Authors certificate of the USSR (f 176106, class G 01 M 1/22, 196 (prototype).

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Claims (1)

Claim The method for determining the deflection of a rotating shaft, which consists in the fact that a contactless sensor is installed at the surface of the cylindrical section of the shaft, a variable component of the signal is isolated, and its amplitude is judged to be deflection, characterized in that, in order to increase the accuracy of determining the deflection, an additional sensor diametrically opposite to the main In addition, each sensor measures the pressure of the environment in the zone of the rotating surface, inverts the signal of one of the sensors, adds it to the signal of the second sensor, and isolates the variable component of the total of the ^35th signal.