Device and method for measuring the deflection of rotating machinery

Abstract

The present invention discloses a device for measuring the deflection of a rotating machine, comprising a regular polygonal magnetic disturbance portion whose center is fixedly arranged on a rotor, a magnetic steel fixedly arranged on one side of the rotor, and a magnetic detection portion arranged corresponding to the magnetic steel and located on one side of the rotor, wherein the magnetic detection portion comprises a magnetic induction coil and a controller connected to the magnetic induction coil. The present invention provides a method for monitoring the deflection of a rotating machine. There is no need to install other measuring devices on the machine. The speed signal of the machine is collected in a certain order, and the deflection and phase of the running rotor are calculated based on the time difference of the speed voltage signal period generated by the magnetic disturbance portion with a polygonal structure on the upper part of the rotor cutting the magnetic lines of force.

Description

Technical Field

[0001] The invention relates to the technical field of rotary machine control, in particular to a device for measuring the deflection amount of a rotary machine. Background Art

[0002] The source of vibration in rotating machinery is the vibration of the rotor, which includes the vibration of the shaft and bearings. Modern vibration monitoring and fault diagnosis systems generally use eddy current sensors to directly detect the vibration of the shaft. This method has made a qualitative leap in the accuracy of vibration monitoring and analysis. Usually, eddy current sensors are used to detect radial vibration of rotating shafts. Radial vibration detection of rotating shafts is a method for studying and solving dynamic balancing problems and the basis for fault diagnosis.

[0003] However, when using eddy current sensors to detect shaft vibration, the non-roundness of the shaft and the flatness of the surface have a great impact on the measurement. The signal caused by the non-roundness of the shaft and the unevenness of the measured surface is called runout. They are superimposed on the real vibration signal, causing errors in people's analysis and processing of vibration, resulting in unsuccessful diagnosis and vibration processing, leading to failures in engineering practice and engineering research. The processing of runout is still a difficult problem in this technical field. Summary of the invention

[0004] The purpose of the present invention is to provide a device for measuring the deflection of a rotating machine in view of the technical defects existing in the prior art.

[0005] The technical solution adopted to achieve the purpose of the present invention is:

[0006] A device for measuring the deflection amount of a rotating machine comprises a regular polygonal magnetic disturbance portion whose center is fixedly arranged on a rotor, a magnetic steel fixedly arranged on one side of the rotor, and a magnetic detection portion arranged corresponding to the magnetic steel and located on one side of the rotor, wherein the magnetic detection portion comprises a magnetic induction coil and a controller connected to the magnetic induction coil.

[0007] The magnetic disturbance part is in the shape of a sheet or a block.

[0008] The joints of the edges of the regular polygon are processed into circular chamfers.

[0009] One of the rounded corners has a shorter radius than the others, and the remaining rounded corners have the same radius.

[0010] The magnetic steel is located between the magnetic detection part and the magnetic disturbance part, and the distance between the magnetic steel and the magnetic disturbance part is 2-10mm.

[0011] The magnetic steel is neodymium iron boron magnetic steel, ferrite magnetic steel, aluminum nickel cobalt magnetic steel or iron boron permanent magnetic material.

[0012] The magnetic steel is an arc-shaped structure with its center on the central axis of the rotor, and the rotating machine is a motor.

[0013] A through hole is formed at the center of the magnetic disturbance part, and the rotor passes through both sides of the through hole to be clamped and positioned.

[0014] The thickness of the magnetic disturbance part is 3-5 cm, and the magnetic disturbance part is a hexagonal structure.

[0015] The magnetic detection unit further comprises a voltage detection mechanism connected to the magnetic induction coil, and the voltage detection mechanism is communicatively connected to the controller.

[0016] A measuring method of the measuring device for measuring the deflection amount of a rotating machine is characterized by comprising the following steps:

[0017] 1) Start sampling and record the time T corresponding to the rotation of each angle of the magnetic disturbance part within a speed cycle i (i=1,2,3,……n), n is the number of sides of the corresponding polygon,

[0018] 2) Calculate the rotor rotation speed f and each time T i The corresponding angle β i , β i =2πfT i , (i=1,2,3,……n);

[0019] 3) β i Bring in The iterative method is used to calculate the rotor offset coordinates (x, y) with a certain step length Δ under the condition that {|x|≤k, |y|≤k} is satisfied, where α i (i=1, 2, 3, ... n) is the calculated angle corresponding to each angle of the magnetic disturbance part.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The method for monitoring the runout of a rotating machine of the present invention does not require the installation of other measuring devices on the machine. The speed signal of the machine is collected in a certain order, and the runout and phase of the running rotor are calculated based on the time difference of the speed voltage signal cycle generated by the magnetic disturbance part of the polygonal structure on the upper part of the rotor cutting the magnetic lines of force. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a schematic diagram of the structure of the device for measuring the deflection amount of a rotating machine according to the present invention;

[0023] Figure 2 Shown is a schematic flow chart of the measuring method of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] The present invention discloses a device for measuring the deflection amount of a rotating machine, including a polygonal magnetic disturbance part 1 whose center is fixedly arranged on a rotor 4, a magnetic steel 3 fixedly arranged on one side of the rotor, and a magnetic detection part 2 arranged corresponding to the magnetic detection part and located on one side of the rotor, wherein the magnetic detection part includes a magnetic induction coil and a controller connected to the magnetic induction coil. The magnetic detection part and the magnetic steel are relatively fixed and will not rotate with the rotor, while the magnetic disturbance part will rotate with the rotor. The magnetic detection part also includes a voltage detection mechanism connected to the magnetic induction coil, and the voltage detection mechanism is communicatively connected to the controller.

[0026] The magnetic disturbance part with a polygonal structure design can be made of metal or magnetic metal. The magnetic steel on the other side forms a magnetic field. When the magnetic disturbance part rotates with the rotor, the magnetic field will change, that is, it will be sensed by the detection part. The magnetic detection part can be an eddy current sensor or other similar components, which converts the change of the magnetic field into voltage change information for analysis.

[0027] The method for monitoring the runout of a rotating machine of the present invention does not require the installation of other measuring devices on the machine, and the runout and phase of the running rotor are calculated based on the time difference of the speed voltage signal cycle generated by the magnetic disturbance part of the polygonal structure on the upper part of the rotor cutting the magnetic lines of force by collecting the speed signal of the machine in a certain order.

[0028] Preferably, the magnetic disturbance part is in the form of a sheet or block, and the magnetic disturbance part is a regular hexagonal structure, and the hexagonal edges are processed into arc chamfers at the junction of the edges, five of which have the same radius, another chamfer has a shorter radius than the others (referred to as short angle), and the remaining chamfers have the same radius (referred to as long angle). When the rotor rotates one circle, there is a peak that is significantly smaller, and this small peak corresponds to the short angle in the speed measuring device.

[0029] When the machine is running, the rotating rotor drives the hexagonal magnetic disturbance part to rotate. The six corners cause the magnetic field around the magnetic detection part to change periodically. The changing magnetic field causes the magnetic detection part to generate an induced voltage. That is, the machine speed is measured using this periodically changing induced voltage. Due to the six-deformation structure on the upper part of the mounting, as well as the design of the long angle and short angle, there is a peak that is significantly smaller when the rotor rotates one circle. This small peak corresponds to the short angle in the speed measuring device. In this way, the speed measurement can be achieved while the runout is measured. At the same time, when the rotor vibrates, the speed measuring device will also cause changes in the magnetic field around the speed measuring coil, which will also cause changes in the speed signal. This changing speed signal corresponds to the rotor runout. By analyzing the induced voltage, the speed and runout can be obtained.

[0030] Furthermore, the magnetic steel is located between the magnetic detection part and the magnetic disturbance part, the distance between the magnetic steel and the magnetic disturbance part is 2-10 mm, and the magnetic steel is a neodymium iron boron magnetic steel, a ferrite magnetic steel, an aluminum nickel cobalt magnetic steel or an iron boron permanent magnetic material. The structure is an arc with the center on the central axis of the rotor.

[0031] The preferred distance setting is adopted, and the detection accuracy is high. As a preferred solution, a through hole is formed in the center of the magnetic disturbance part, and the rotor is clamped and positioned through the two sides of the through hole. Generally speaking, the thickness of the magnetic disturbance part is 3-5cm. The device can be easily assembled on the shaft of the rotor by adopting the set clamping positioning. Moreover, as a further extension, multiple magnetic disturbance parts, magnetic steels and magnetic detection parts can be assembled on the rotor, and the same type of deflection measurement can be performed in multiple different orientations, which enhances the accuracy of the swing measurement. In addition, when performing data analysis, the processing difficulty is simplified because of the same speed waveform.

[0032] Specifically, the rotating machinery can be a motor, a steam turbine, a gas turbine, a centrifugal and axial compressor, a fan, a pump, a turbine, a generator and an aircraft engine, etc., which are widely used in the electric power, petrochemical, metallurgy and aerospace sectors.

[0033] The rotor runout is related to the time of the voltage signal cycle generated by the magnetic disturbance part cutting the magnetic lines of force; according to the structure of the magnetic disturbance part and the speed voltage signal it generates, the corresponding time of each angular rotation of the speed measuring device is recorded in a specific sampling order; the rotor runout is calculated based on the relationship between the runout and the above time. Taking the regular hexagonal magnetic disturbance part as an example,

[0034] The measurement method comprises the following steps:

[0035] Step 1: Start sampling from the zero-crossing point of the speed signal peak, and record the time T corresponding to the rotation of each angle of the magnetic disturbance part within a speed cycle. i (i=1,2,3,4,5,6);

[0036] The sampling order is that when the rotor rotates one circle and the small peak voltage of the speed signal is 0V, sampling begins. i (i=1,2,3,4,5,6) respectively correspond to the time required for the speed signal to change from zero point to peak point to zero point to trough point to zero point. T1 corresponds to the short angle of the speed measuring device, T i (i=2,3,4,5,6) correspond to the five long corners of the speed measuring device respectively.

[0037] Assuming the rotor rotation center is O'(x,y), the rotor runout and phase angle are:

[0038]

[0039] With the rotor's rotation center as O'(x,y) and the vertex, when the rotor rotates one circle, the angle between adjacent angles can be expressed as:

[0040]

[0041]

[0042] Each corresponding angle is calculated to reduce the error caused by the workpiece processing error of the hexagonal magnetic disturbance part to the subsequent calculation, thereby improving the accuracy.

[0043] Step 2: According to the T recorded in step 1 i , calculate the rotor rotation speed f and each time T i The corresponding angle β i β i =2πfT i (i=1,2,3,4,5,6)

[0044] Step 3: Substitute (3) calculated in step 2

[0045] T i ——Measure the time required to rotate to the corresponding angle.

[0046]

[0047] According to the time T required for the rotor to rotate the corresponding angle i , using the iterative method and a certain step size, according to formula (4),

[0048] The offset coordinates (x,y) of the rotor can be calculated.

[0049] In step 3, an iteration method is used, and different step sizes can be used to improve the calculation accuracy. In step 3, the offset coordinates of the rotor must satisfy |x|≤k, |y|≤k, where k is the distance between the magnetic disturbance part and the machine stator.

[0050] By adopting the method for measuring the deflection amount of rotating machinery described in the present invention, the deflection and phase conditions of the rotating machinery can be quickly obtained by sampling and calculating the speed signal of the rotating machinery in a certain order, without installing additional measuring devices, thereby providing a means for online monitoring of the operating status of the rotating machinery.

[0051] A method for measuring the deflection of a rotating machine includes the following steps:

[0052] Taking the rotor runout as (0.050mm, -0.036mm), the speed measuring device long angle corresponding to the speed voltage signal amplitude is 3V (single peak value), the speed measuring device short angle corresponding to the speed voltage signal amplitude is 2.4V (single peak value), taking the speed of 155 cycles / minute as an example to explain the present invention in detail:

[0053] Step 1: Start sampling from the zero-crossing point of the small peak of the speed signal, and record the time corresponding to the rotation of each angle of the magnetic disturbance part within a speed cycle, which is T1=1.07503ms, T2=1.07956ms, T3=1.08108ms, T4=1.07725ms, T5=1.07211ms, T6=1.06670ms;

[0054] Step 2: According to the T recorded in step 1 i , calculate the rotor rotation speed is 155 cycles / minute and each time T i The corresponding angles are β1 = 60.011°, β2 = 60.114°, β3 = 60.102°, β4 = 60.053°, β5 = 59.954°, β6 = 59.766°;

[0055] Step 3: Substitute the β calculated in step 2 i Substitute equation (2) into The iteration method is used with a step size of 0.001 mm. All Δ are calculated in the range of {|x|≤k, |y|≤k} until Δ min , calculate Δ min The corresponding offset coordinates (x, y) are (0.050mm, -0.036mm). This proves that this method is stable and reliable.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A measuring method for a measuring device of a rotating machine deflection, characterized in that: The device for measuring the deflection amount of a rotating machine comprises a regular polygonal magnetic disturbance part whose center is fixedly arranged on a rotor, a magnetic steel fixedly arranged on one side of the rotor, and a magnetic detection part arranged corresponding to the magnetic steel and located on one side of the rotor, wherein the magnetic detection part comprises a magnetic induction coil and a controller connected to the magnetic induction coil; The magnetic steel is located between the magnetic detection part and the magnetic disturbance part, and the distance between the magnetic steel and the magnetic disturbance part is 2-10mm; The magnetic steel is an arc-shaped structure with its center on the central axis of the rotor, and the rotating machine is a motor; The magnetic detection unit further includes a voltage detection mechanism connected to the magnetic induction coil, and the voltage detection mechanism is communicatively connected to the controller; The measuring method comprises the following steps: 1) Start sampling and record the time T corresponding to the rotation of each angle of the magnetic disturbance part within a speed cycle i (i=1,2,3,……n), n is the number of sides of the corresponding polygon, 2) Calculate the rotor rotation speed f and each time T i The corresponding angle β i ,β i =2πfT i ,(i=1,2,3,……n); 3) β i Bring in The iterative method is used to calculate the rotor offset coordinates (x, y) with a certain step length Δ under the condition that {|x|≤k, |y|≤k} is satisfied, where α i (i=1, 2, 3, ... n) is the calculated angle corresponding to each angle of the magnetic disturbance part.

2. The measuring method according to claim 1, characterized in that: The magnetic disturbance part is in the shape of a sheet or a block.

3. The measuring method according to claim 1, characterized in that: The joints of the edges of the regular polygon are processed into circular chamfers.

4. The measuring method according to claim 3, characterized in that: One of the rounded corners has a shorter radius than the others, and the remaining rounded corners have the same radius.

5. The measuring method according to claim 1, characterized in that: The magnetic steel is neodymium iron boron magnetic steel, ferrite magnetic steel, aluminum nickel cobalt magnetic steel or iron boron permanent magnetic material.

6. The measuring method according to claim 1, characterized in that: A through hole is formed at the center of the magnetic disturbance part, and the rotor passes through both sides of the through hole to be clamped and positioned.

7. The measuring method according to claim 1, characterized in that: The thickness of the magnetic disturbance part is 3-5 cm, and the magnetic disturbance part is a hexagonal structure.

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