Device and method for measuring air gap between stator and rotor of generator

Abstract

The invention relates to the technical field of generator air gap measurement, in particular to a device and a method for measuring an air gap between a stator and a rotor of a generator, and aims to solve the problems of low manual detection efficiency and large deviation in generator air gap measurement. Comprising a positioning ring, a detection assembly and a measurement assembly. A plurality of probes are arranged on the detection assembly, displacement sensors are arranged in the probes, and the displacement sensors are in signal connection with a central processing unit; the positioning ring is used for sleeving the outer circumferential wall of the rotor, the measuring assembly is used for pushing the detection assembly to make the detection assembly abut against the stator, and the displacement sensor is used for recording displacement data of the probe and feeding back the displacement data to the central processing unit. Through cooperative detection of the positioning ring and the detection assembly and cooperative data processing of the displacement sensor and the central processing unit, displacement data can be collected in real time and transmitted and processed in a centralized mode, the automation and datamation degree of air gap measurement is greatly improved, and low efficiency and high errors of traditional manual air gap measurement are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of generator air gap measurement, and particularly to a measurement device and method for the air gap between the stator and rotor of a generator. Background Art

[0002] As a key device in the power system, the operation stability of a generator is directly related to the safety and efficiency of the entire power system; during the operation of the generator, the rotor winding must maintain an accurate relative position with the stator when rotating at high speed, and the radial gap between the two, that is, the so-called air gap between the stator and the rotor, is also called the air gap; under long-term operation or high-load operation conditions, the rotor axis may be eccentric or deformed, or there may be assembly errors or uneven thermal expansion in the stator core, etc., which may all lead to uneven air gaps, and further induce faults such as electromagnetic imbalance, local heating, mechanical vibration, and even insulation damage. Therefore, the detection of the air gap between the stator and rotor has become a key link in the condition-based maintenance and fault warning of generators.

[0003] Among the existing air gap detection methods, the conventional ones are the feeler gauge method and the lead wire method, which are cumbersome to operate and have low measurement accuracy; in addition, there are also laser ranging or optical interference methods, but in practical applications, they are restricted by factors such as the surface roughness of the stator and electromagnetic interference, and the equipment cost is relatively high.

[0004] Therefore, there is a need for a technology with high measurement accuracy that can accurately find the distribution position of the abnormal air gap area and promptly check and repair the stator and rotor. Summary of the Invention

[0005] The technical problem to be solved by the present invention is the problems of slow measurement efficiency and inaccurate accuracy when measuring the air gap between the stator and rotor of a generator using the existing technology. The purpose is to provide a measurement device and method for the air gap between the stator and rotor of a generator, which can quickly detect the air gap between the stator and rotor through multiple positions.

[0006] The present invention is achieved through the following technical solutions: A measurement device for the air gap between the stator and rotor of a generator, comprising: A positioning ring, one end of which is provided with a detection component; On the outer peripheral wall of the detection component, a plurality of probes are arranged in an annular array, a displacement sensor is arranged inside the probe, and a plurality of the displacement sensors are signal-connected to a central processing unit; A measurement component, which is arranged on the rotating shaft of the generator; Among them, the positioning ring is used to sleeved on the outer peripheral wall of the rotor, so that the positioning ring and the detection component are located in the air gap. The measuring component is used to push the detection component to make the detection component contact with the stator. The displacement sensor is used to record the displacement data of the probe and feedback it to the central processing unit.

[0007] In the above technical solution, through the cooperation and detection of the positioning ring and the detection component, and the collaborative processing of data by the displacement sensor and the central processing unit, the displacement data can be collected in real time and transmitted for centralized processing, greatly improving the automation and dataization degree of air gap measurement, and avoiding the low efficiency and high error of traditional manual air gap measurement.

[0008] In some alternative technical solutions, the detection component is a measuring ring. The measuring ring and the positioning ring are coaxially arranged. The diameter of the measuring ring is larger than that of the positioning ring. The measuring ring and the positioning ring are fixedly connected. The measuring component is a pushing shaft, and the diameter of the pushing shaft is larger than that of the measuring ring.

[0009] In the above technical solution, when the measuring ring is measuring, through the push of the pushing shaft, the measuring ring can be directly pushed into the air gap, and it can be intuitively seen whether there is a problem with the air gap.

[0010] In some alternative technical solutions, the detection component is a plurality of measuring pieces. The measuring pieces are arc-shaped and are annularly arrayed along the center of the positioning ring and are coaxially arranged with the positioning ring. The probes are annularly and evenly distributed on the outer peripheral wall of the measuring pieces. The measuring component is a pushing member. When the pushing member moves along the measuring pieces, the distances from the plurality of measuring pieces to the center of the positioning ring increase synchronously.

[0011] In the above technical solution, a plurality of measuring pieces are evenly distributed around the detection component. When being squeezed by the pushing member, they can move towards the stator synchronously, reducing the measurement error.

[0012] In some alternative technical solutions, an annular groove is opened on the outer peripheral wall of the positioning ring close to one side of the measuring piece. A limiting block is fixedly connected to the measuring piece. One end of the measuring piece is located on the annular groove, and the other end of the measuring piece is located outside. A plurality of first springs connected to the measuring piece are arranged on the annular groove. The pushing member has a frustum-shaped structure, and the end with the smallest diameter of the pushing member faces the positioning ring. The side of the limiting block facing the center of the positioning ring is an inclined surface.

[0013] In the above technical solution, under the action of the first spring and the limiting block with an inclined surface, the measuring piece can be quickly unfolded or folded during measurement, improving the detection efficiency.

[0014] In some alternative technical solutions, a plurality of grooves are formed on one end surface of the positioning ring, and connecting holes are formed on both side surfaces of the grooves. A plurality of hinge blocks corresponding to the grooves are fixedly connected to one side of the measuring piece facing the positioning ring. Connecting shafts rotatably connected to the connecting holes are respectively arranged at both ends of the hinge block. The pushing member is of a cylindrical structure, and a plurality of push rods abutting against the measuring piece are arranged on the outer peripheral wall of the pushing member. A second spring connected to the pushing member is arranged at the bottom end of the push rod, and the top end of the push rod is a bevel surface.

[0015] In the above technical solution, the measuring piece is rotatably connected to the positioning ring. During measurement, even if part of the measuring piece has abutted against the stator, the push rod can still drive other measuring pieces to rotate continuously, ensuring that complete measurement data can be obtained at each measurement point even when there are local abnormalities.

[0016] In some alternative technical solutions, with the center of the rotor as the center, the positioning ring is equally divided into four detection areas, and one measuring piece is arranged in each detection area.

[0017] In the above technical solution, the positioning ring is equally divided into four detection areas with the center of the rotor as the center, and the measuring pieces are respectively located in the four detection areas. Each measuring piece can independently record the air gap of the current area, accelerating the detection efficiency and improving the detection accuracy.

[0018] In some alternative technical solutions, a probe is arranged on the measuring piece of each detection area. When the probe abuts against the inner peripheral wall of the stator in the detection area, the detection radius is obtained, and the air gap is calculated using the detection radius.

[0019] In the above technical solution, when the probe on the measuring piece in each detection area contacts the stator in the corresponding area, it represents the end of the measurement. At the same time, the probe will record the data of the corresponding area, which is obtained through subsequent data processing and calculation.

[0020] In some alternative technical solutions, the probe of each measuring piece is represented by the distance from the current position to the center of the positioning ring as l T , the distance from the center of the rotor to the probe is l Z , and the distance from the center of the rotor to the inner peripheral wall of the stator is l D ; The central processing unit draws a first image by making a circle with l Z as the radius, draws a second image by making a circle with l D as the radius, and according to before and after measurement l TCompare with the first image and the second image respectively.

[0021] In the above technical solution, based on the straight-line distance from the probe to the center of the positioning ring, compare with the first image before measurement and the second image after measurement, locate the abnormal area, evaluate the deviation amount, and enhance the detection accuracy and efficiency.

[0022] The second aspect of the present invention relates to a method for measuring the air gap between the stator and rotor of a generator. The air gap is measured according to the first aspect of the present invention, and the measurement is carried out through the following steps: Step 1, preparation before measurement; Step 2, install the positioning ring and the detection component, and start the central processing unit. Divide the positioning ring into four detection areas with the center of the rotor as the center. Step 3, measure and record the initial data of the probe, and feed the data back to the central processing unit for comparison. Step 4, control the detection component to move towards the stator, record the final data of the probe, and feed the data back to the central processing unit for comparison. Step 5, generate a report on the comparison results of Step 3 and Step 4.

[0023] In the above technical solution, from equipment layout to data output in five clear steps, an effective data comparison is naturally formed, and a comparison report is output, which is more efficient and accurate than traditional detection techniques.

[0024] In some alternative technical solutions, Step 2 includes: Step 21, positioning ring installation; sleeved the positioning ring on the rotor, keep the two coaxial, and install the detection component on the positioning ring. Step 22, preliminary inspection; check whether the detection component is in the initial state and check whether the probe is damaged. Step 3 includes: Step 31, initial data generation; before the probe moves, the displacement sensor records and generates the position of the probe, and feeds the data back to the central processing unit. Step 32, data comparison before measurement; When the straight-line deviation of the probe from the center of the positioning ring in any detection area deviates from the first image, record this detection area.

[0025] In the above technical solution, a measurement positioning is carried out once before the measurement equipment is started to detect the preliminary deviation and avoid errors in subsequent measurement data.

[0026] In some alternative technical solutions, Step 32 includes: Step 321, the central processing unit calculates according to the distance from the center of the rotor to the probe l ZDraw a first image with a certain radius as the circle; Step 322: Compare the straight lines from the probes in the four detection areas to the center of the positioning ring with the first image respectively, and record the comparison results; In the above technical solution, based on the first image, compare and judge the results according to the straight-line distance measured from the probe to the center of the positioning ring before measurement.

[0027] In some alternative technical solutions, the step 4 includes: Step 41: Move the detection component to the inner peripheral wall of the stator; control the pushing member to push the detection component to move towards the inner peripheral wall of the stator until it touches; Step 42: The displacement sensor records the data after each probe touches the inner peripheral wall of the stator and feeds it back to the central processing unit; Step 43: Compare the measured data; obtain the air gap distance.

[0028] In the above technical solution, by using the method of comparing the data in multiple detection areas, when the straight line distance from the middle probe to the center of the positioning ring deviates from the second image, the abnormal area can be quickly locked, and any deviation of the data in any detection area can be captured in time, ensuring the accuracy of the air gap measurement.

[0029] In some alternative technical solutions, the step 43 includes: Step 431: Measure the distance from the center of the rotor to the inner peripheral wall of the stator l D ; According to l D Draw a second image with a certain radius as the circle; Step 432: Obtain the straight lines from the middle probes on the four measuring pieces to the center of the positioning ring; Step 433: Compare the straight lines from the middle probes in the four detection areas after measurement to the center of the positioning ring with the second image respectively, and record the comparison results.

[0030] In the above technical solution, based on the second image, compare and judge the results according to the straight-line distance measured from the middle probe to the center of the positioning ring after measurement.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. In the present invention, by moving the pushing member to control several measuring pieces to move towards the stator synchronously, record the position data when the probes touch the stator, and can continue to move the measuring pieces after some measuring pieces touch the stator, so that the measuring pieces that have not touched the stator can touch the stator; 2. In the present invention, the positioning ring is equally divided into four detection areas with the center of the rotor as the center. A measuring piece is arranged in each of the four detection areas. When using the probes distributed on the measuring piece for detection and recording, measurement can be carried out synchronously in the four detection areas, and the data in the four detection areas can be recorded and compared separately, so as to quickly and accurately locate the abnormal area of the air gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not constitute a limitation to the embodiments of the present invention. In the drawings: Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention; Figure 2 is a cross-sectional view of Embodiment 1 of the present invention; Figure 3 is a schematic structural diagram of Embodiment 2 of the present invention; Figure 4 is a cross-sectional view of Embodiment 2 of the present invention; Figure 5 is Figure 4 a partial enlarged view of A in Figure 6 is Figure 5 a partial enlarged view of A1 in Figure 7 is a schematic structural diagram of Embodiment 3 of the present invention Figure 1 ; Figure 8 is a schematic structural diagram of Embodiment 3 of the present invention Figure 2 ; Figure 9 is a cross-sectional view of Embodiment 3 of the present invention; Figure 10 is Figure 9 a partial enlarged view of B in Figure 11 is a schematic structural diagram of the positioning ring and the measuring piece in Embodiment 3 of the present invention; Figure 12 is a schematic diagram of the positions of the measuring pieces in the four detection areas of the positioning ring in the present invention Figure 1 ; Figure 13 is a schematic diagram of the positions of the measuring pieces in the four detection areas of the positioning ring in the present invention Figure 2 ; Figure 14 is the flow of the present invention Figure 1 ; Figure 15 is the flow of the present invention Figure 2 .

[0033] What the reference numerals represent are: 1. Rotor; 2. Stator; 3. Positioning ring; 31. Measuring ring; 4. Measuring piece; 41. Limit block; 42. Hinge block; 5. Probe; 6. Pushing member; 61. Push rod; 62. Extrusion shaft; 71. First spring; 72. Second spring. Detailed implementation mode

[0034] To make the purpose, technical solution and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and do not limit the present invention. It should be noted that the present invention is already in the actual R & D and use stage.

[0035] Embodiment 1 As Figures 1 to 2 shown, this embodiment provides a measuring device for the air gap between the stator and rotor of a generator, including: A positioning ring 3, with a detection component provided at one end of the positioning ring 3; A plurality of probes 5 are arranged on the outer peripheral wall of the detection component in a circumferentially arrayed manner. A displacement sensor is arranged inside the probe 5, and a plurality of displacement sensors are signal-connected to a central processing unit; A measuring component, which is arranged on the rotating shaft of the generator; Among them, the positioning ring 3 is used to be sleeved on the outer peripheral wall of the rotor 1, so that the positioning ring 3 and the detection component are located in the air gap. The measuring component is used to push and extrude the detection component to make the detection component contact the stator 2. The displacement sensor is used to record the displacement data of the probe 5 and feedback it to the central processing unit.

[0036] As Figures 3 to 5 shown, the detection component is a measuring ring 31. The measuring ring 31 and the positioning ring 3 are coaxially arranged. The diameter of the measuring ring 31 is larger than that of the positioning ring 3. The measuring ring 31 and the positioning ring 3 are fixedly connected. The measuring component is an extrusion shaft 62, and the diameter of the extrusion shaft 62 is larger than that of the measuring ring 31.

[0037] Specifically, in the air gap measurement of this embodiment, after the generator stops and cools down, the positioning ring 3 is sleeved on the rotor 1. The measuring ring 31 is fixedly connected to the positioning ring 3 and coaxial. Preferably, the measuring ring 31 should be a complete circle. In this embodiment, the thickness of the measuring ring 31 is the same as the distance of the air gap of the generator to be measured. Different specifications of positioning rings 3 and measuring rings 31 can be replaced to measure different generator air gaps. When the measuring ring 31 is pushed towards the air gap between the stator 2 and the rotor 1 by the pushing shaft 62, if the measuring ring 31 passes through completely, it means that the air gap is intact and the stator 2 and the rotor 1 are operating normally; if the measuring ring 31 has difficulty entering the air gap and is blocked or there is a gap between the measuring ring 31 and the stator 2, it indicates that there is a certain problem between the stator 2 and the rotor 1 and corresponding repairs are needed; this embodiment is applicable to detection methods with low precision.

[0038] Embodiment 2 As Figures 3 to 5 shown, the detection component is several measuring pieces 4. The measuring pieces 4 are arc-shaped and are distributed in an annular array along the center of the positioning ring 3 and are coaxially arranged with the positioning ring 3. The probes 5 are evenly distributed in a ring on the outer peripheral wall of the measuring pieces 4. The measuring component is a pushing member 6. When the pushing member 6 moves along the measuring pieces 4, the distances from several measuring pieces 4 to the center of the positioning ring 3 increase synchronously.

[0039] As Figures 3 to 5 shown, an annular groove is formed on the outer peripheral wall of the positioning ring 3 on the side close to the measuring pieces 4. A limiting block 41 is fixedly connected to the measuring piece 4. One end of the measuring piece 4 is located in the annular groove, and the other end of the measuring piece 4 is located outside. Several first springs 71 connected to the measuring piece 4 are arranged on the annular groove. The pushing member 6 has a frustum-shaped structure. The end with the smallest diameter of the pushing member 6 faces the positioning ring 3. The side of the limiting block 41 facing the center of the positioning ring 3 is an inclined surface.

[0040] The difference between this embodiment and Embodiment 1 lies in the different detection components and detection methods; in this embodiment, the number of measuring pieces 4 is preferably four, and they are arranged in a circular array around the center of the positioning ring 3. The four measuring pieces 4 are arc-shaped, and the extension lines of their arcs can form a circle. The inside of the frustum-shaped pushing member 6 is a hollow structure and can slide on the rotating shaft of the generator. The radius of the small end of the pushing member 6 is smaller than the distance from the measuring pieces 4 to the center of the positioning ring 3 when they are closed, and a part of the measuring piece 4 is located outside.

[0041] The air gap detection principle of this embodiment is as follows: The pushing member 6 is pushed towards the positioning ring 3. A plurality of measuring pieces 4 are extruded by the inclined surface of the pushing member 6. The limiting blocks 41 drive the measuring pieces 4 to move towards the stator 2 respectively. One end of the first spring 71 is connected to the annular groove, and the other end is connected to the measuring piece 4. A plurality of first springs 71 fix a part of the measuring piece 4 on the annular groove, which can prevent the end of the measuring piece 4 located outside from tilting and losing balance. After the probes 5 on a plurality of measuring pieces 4 contact the inner peripheral wall of the stator 2, the pushing member 6 cannot move any further. At this time, the displacement sensor in the probe 5 also records the final data and feeds it back to the central processing unit.

[0042] In this embodiment, under the push of the same pushing member 6, the four measuring pieces 4 move towards the stator 2 synchronously. If there is a problem with the air gap, such as the air gap distance of one of the measuring pieces 4 being the narrowest, then this measuring piece 4 will contact the stator 2 first. Since the pushing member 6 forces the measuring piece 4 to move by pushing the limiting block 41 fixed to the measuring piece 4, after one of the measuring pieces 4 contacts the stator 2, the stator 2, together with the inclined surfaces of the frustum-shaped pushing member 6 and the limiting block 41, jointly limit and fix this measuring piece 4, resulting in the pushing member 6 being unable to move any further. This also causes the other measuring pieces to not be able to contact the stator at the normal or larger air gap positions. At this time, the problem of the local air gap can be observed and judged, and the displacement sensor will record and feedback the data for subsequent comparison. After the measurement is completed, the measuring device can be taken out.

[0043] It should be noted that the natural length of the first spring 71 can make the measuring piece 4 fit on the positioning ring 3. Only when subjected to the thrust of the pushing member 6, a plurality of measuring pieces 4 will open and leave the positioning ring 3; in addition, the length of the positioning ring 3 should be long enough, with a length greater than or equal to the length of the stator 2, or the generator is completely disassembled, and a fixing ring is provided at the other end of the stator 2 relative to the pushing member 6. Both of the above are used to fix the positioning ring 3 to prevent the positioning ring 3 from moving during the detection.

[0044] Embodiment 3 As Figures 6 to 10 shown, a plurality of grooves are provided on one end surface of the positioning ring 3, and connecting holes are provided on both side surfaces of the grooves. A plurality of hinge blocks 42 corresponding to the grooves are fixedly connected to the side of the measuring piece 4 facing the positioning ring 3. Connecting shafts rotatably connected to the connecting holes are respectively provided at both ends of the hinge block 42. The pushing member 6 is of a cylindrical structure, and a plurality of push rods 61 in contact with the measuring piece 4 are provided on the outer peripheral wall of the pushing member 6. A second spring 72 connected to the pushing member 6 is provided at the bottom end of the push rod 61, and the top end of the push rod 61 is an inclined surface.

[0045] Specifically, the measuring piece 4 in this embodiment is the same as that in Embodiment 2, with a quantity of four pieces, and it is also arc-shaped. The difference lies in the connection method between the measuring piece 4 and the positioning ring 3 and the measuring method of the air gap. In this embodiment, the measuring piece 4 and the positioning ring 3 are rotationally connected through a connecting shaft. The pushing member 6 is of a cylindrical structure. Four push rods 61 are provided on the pushing member 6 and correspond to the four measuring pieces 4 one by one. When moving the pushing member 6 according to the method in Embodiment 2, the push rod 61 squeezes the measuring piece 4 to make it rotate towards the stator 2 until the probe 5 fits against the inner peripheral wall of the stator 2.

[0046] The following is an example to illustrate the difference between this embodiment and Embodiment 2. During the measurement, if the probes 5 of three of the measuring pieces 4 have already contacted the stator 2 and the last one has not yet contacted the stator 2, it is already clear that there is a problem with the air gap at this time, but the accurate position data of the air gap still needs to be measured. Compared with Embodiment 2, the pushing member 6 in this embodiment can continue to move. The surface of the push rod 61 in contact with the measuring piece 4 is an inclined surface. The other three measuring pieces 4 are abutted against the stator 2 and are also connected to the positioning ring 3. Therefore, even if the pushing member 6 continues to move, it will not be interfered. On the contrary, the push rod 61 will be squeezed by these three measuring pieces 4 and retract into the pushing member 6 through the second spring 72, while the pushing member 6 at the position of the last measuring piece 4 will continue to push the measuring piece 4 to rotate until it contacts the stator 2.

[0047] After the measurement is completed, take out the measuring device, and this embodiment can accurately find the location where the air gap has problems.

[0048] Embodiment 4 As Figures 6 to 12 shown, this embodiment provides a method for measuring the air gap between the stator and rotor of a generator. The air gap is measured according to the measuring device in Embodiments 2-3, and the measurement is carried out through the following steps: Step 1, preparation before measurement; Step 2, install the positioning ring 3 and the detection component, and start the central processing unit. With the center of the rotor 1 as the center, divide the positioning ring 3 into four detection areas; Step 3, measure and record the initial data of the probe 5, and feed the data back to the central processing unit for comparison; Step 4, control the detection component to move towards the stator 2, record the final data of the probe 5, and feed the data back to the central processing unit for comparison; Step 5, generate a report on the comparison results of Step 3 and Step 4.

[0049] Specifically, in the pre-measurement preparation stage of Step 1, the generator needs to be shut down and the rotor 1 needs to be cooled. During this period, according to information such as the generator model and parameters, the parameters of the stator 2, rotor 1, and air gap under normal conditions of the generator can be recorded and input into the central processing unit. In Step 5, that is, after the measurement in Step 4 is completed, a report is generated for the results of Steps 3 and 4. According to the measured air gap data, it is judged whether maintenance is required. Finally, the measuring equipment is disassembled and recycled.

[0050] Step 2 includes: Step 21, installation of the positioning ring 3: The positioning ring 3 is sleeved on the rotor 1, and the two are kept coaxial. The detection component is installed on the positioning ring 3; Step 22, preliminary inspection: Check whether the detection component is in the initial state and check whether the probe 5 is damaged; Step 3 includes: Step 31, generation of initial data: Before the probe 5 moves, the displacement sensor records and generates the position of the probe 5, and feeds the data back to the central processing unit; Step 32, data comparison before measurement: When the straight line from the probe 5 to the center of the positioning ring 3 in any detection area deviates from the first image, record this detection area; Step 321, the central processing unit makes a circle with the distance l Z from the center of the rotor 1 to the probe 5 as the radius to draw the first image; Step 322, respectively compare the straight lines from the probe 5 to the center of the positioning ring 3 in the four detection areas with the first image, and record the comparison results.

[0051] Specifically, after the installation in Step 2 is completed, Step 3 is mainly used to record the data before measurement, and can detect and judge the condition of the rotor 1 or whether the measuring equipment is installed in place.

[0052] Step 4 includes: Step 41, move the detection component to the inner peripheral wall of the stator 2: Control the push member 6 to push the detection component to move towards the inner peripheral wall of the stator 2 until it abuts; Step 42, the displacement sensor records the data after each probe 5 abuts on the inner peripheral wall of the stator 2 and feeds it back to the central processing unit; Step 43, data comparison after measurement to obtain the air gap distance; Step 431, measure the distance from the center of the rotor 1 to the inner peripheral wall of the stator 2 l D ; According to l D make a circle with the radius to draw the second image; Step 432, obtain the straight lines from the probes 5 in the middle parts of the four measuring pieces 4 to the positioning ring 3; Step 433: Compare the straight lines from the probes 5 in the middle of the four detection areas after measurement to the center of the positioning ring 3 with the second image respectively, and record the comparison results.

[0053] Step 434: Compare the probe 5 data at the head and tail of each measuring piece in the four detection areas after measurement; when the displacement sensor of any one of the probes 5 at the head, tail, from the head to the middle, and from the tail to the middle in any detection area detects the stator 2, record it; specifically, in Steps 3 and 4, record the data of the probes 5 on the installed measuring piece 4 once and compare it with the first image; after the measuring piece 4 is unfolded, record the position data of the probes 5 again and compare it with the second image; according to the differences in the comparison results and combined with the measured air gap distance, judge whether there is a problem with the air gap of the current generator and the area where the problem is located.

[0054] Embodiment 5 This embodiment measures the air gap between the stator 2 and the rotor 1 based on the measuring device in Embodiment 3 and the measuring method in Embodiment 4.

[0055] As Figures 6 to 12 shown, with the center of the rotor 1 as the center, the positioning ring 3 is equally divided into four detection areas, and one measuring piece 4 is set in each measuring area; Preferably, as Figure 12 and Figure 13 shown, the rotor 1 is equally divided into four detection areas. In the figure, x and y represent directions for positioning use. There is one measuring piece 4 in each of the four detection areas. Let the initial radius of each measuring piece 4 be ri; r represents the initial radius of the measuring piece 4, i represents the detection area, and i is equal to 1, 2, 3, 4; taking the detection area in the upper right corner of the figure as the first detection area, rotating counterclockwise around the center of the rotor 1, they are the second detection area, the third detection area, and the fourth detection area respectively.

[0056] It should be noted that when the probe 5 of the measuring piece 4 abuts against the inner peripheral wall of the stator 2 in the corresponding detection area, the radius of the measuring piece 4 is represented as Ri, and R represents the radius when the measuring piece 4 abuts against the stator 2.

[0057] The air gap between the stator 2 and the rotor 1 is expressed as: ; where h represents the air gap distance in each detection area, and d represents the thickness of the probe 5; Specifically, this formula is used to measure the size of the air gap at each place in the four detection areas. It should also be noted that as described above, in the present invention, i represents the detection area. For example, h1 represents the air gap distance in the first detection area, R1 represents the radius from the measuring piece 4 in the first detection area to the center of the positioning ring 3 after abutting against the stator 2, and r1 represents the radius from the measuring piece 4 in the first detection area to the center of the positioning ring 3 before measurement.

[0058] Compare the measured air gap h with the initial air gap h0, which is obtained as follows: ; where r D represents the inner diameter of the stator 2; the above formula is used to compare the air gap distance obtained after measurement; when h i is greater than or less than h0, the stator 2 or the rotor 1 in the current detection area needs to be detected and repaired.

[0059] In addition, it should be noted that the diameters and air gaps of the stator 2 and the rotor 1 in each generator are determined; similarly, the thickness of the measuring piece 4 is also constant. It should be noted that the measuring piece 4 in the present invention is a sector-shaped ring and is coaxial with the positioning ring 3. The ring includes an outer surface and an inner surface. The radius of the measuring piece 4 described in the present invention refers to the distance from its outer surface to the center of the positioning ring 3. In the present invention, the measuring piece 4 is sleeved on the rotor 1. The measuring piece 4 has a thickness. Taking the sleeved measuring piece 4 as the initial air gap, the inner diameter of the stator 2 needs to be subtracted by the distance ri from the outer surface of the measuring piece 4 to the center of the positioning ring 3, that is, a standard initial air gap h0 is obtained. Since the air gap is normally circular, the hi measured in the four detection areas can all be compared with the initial air gap h0. When hi is greater than or less than h0, it means that there is a problem with the air gap in the current detection area.

[0060] Embodiment 6 This embodiment is based on the measurement methods of Embodiment 4 and Embodiment 5, and specifically describes the measurement methods of the measuring piece 4 and the probe 5.

[0061] Represent the probe 5 on each measuring piece 4 as Ti; Preferably, the total number of probes 5 on each measuring piece 4 is odd and at least 5. The probes 5 at the head, middle, and end are used for positioning and can timely determine the linear distance from themselves to the center of the positioning ring 3; the probe 5 at the head of each measuring piece 4 is represented as , the probe 5 in the middle is represented as , the probe 5 at the end is represented as , the data of each probe 5 before and after measurement are fed back to the central processing unit. The distance from the current position of the probe 5 on each measuring piece 4 to the center of the positioning ring 3 is represented as l T .

[0062] Specifically, taking the measuring piece 4 in the first detection area as an example, the head probe is , the middle probe is , and the end probe is .

[0063] Specifically, the actual distances from the probes 3 at the head, middle, and tail ends of the measuring piece 4 to the center of the positioning ring 3 before measurement are respectively represented as , and ; the actual distances from the probes 3 at the head, middle, and tail ends of the measuring piece 4 to the center of the positioning ring 3 after measurement are respectively represented as , and .

[0064] The distance from the center of the rotor 1 to the probe 3 is l Z , and the distance from the center of the rotor 1 to the inner peripheral wall of the stator 2 is l D ; The central processing unit draws a first image by making a circle with the distance l Z from the center of the rotor 1 to the probe 3 as the radius, draws a second image by making a circle with the distance l D from the center of the rotor 1 to the inner peripheral wall of the stator 2 as the radius, and draws a straight line from the rotor 1 to the center of the positioning ring 3 according to l Z and l D respectively.

[0065] Specifically, the straight line from each of the probes 5 to the center of the positioning ring 3 before measurement is compared with the first image, and the straight line from each of the probes 5 to the center of the positioning ring 3 after measurement is compared with the second image. When the straight line from the probe 5 to the center of the positioning ring 3 deviates from the first image or the second image, the area where the probe 5 is located needs to be detected and repaired.

[0066] It should be noted that the probe 5 is cylindrical, the displacement sensor is arranged on the arc surface on the side of the probe 5 away from the measuring piece 4, and the position information detected by the displacement sensor is the distance from the side of the probe 5 away from the measuring piece 4 to the center of the positioning ring 3. Preferably, a linear displacement sensor is used; l Z and l D of the present invention are both based on the normal air gap, and information is input into the central processing unit in advance as a subsequent measurement reference.

[0067] Taking the normal air gap as an example, it should also be noted that after the positioning ring 3 is installed, all four measuring pieces 4 are in contact with the outer peripheral wall of the rotor 1. Since the positioning ring 3, the rotor 1, and the measuring piece 4 are all coaxial, the straight-line distance l Tare all equal, and the linear distances from the three probes 5 used for positioning on the measuring piece 4 to the center of the positioning ring 3 in each detection area 、 and are also all equal; the first image is a circle formed with l Z as the radius. When the air gap is normal, 、 and will all pass through the center of the first image and will not deviate from the first image. The deviation from the first image referred to in the present invention means deviating from the center of the circle formed by the first image. The same applies to the second image

[0068] After the measurement is completed, the probes 5 on the four measuring pieces 4 will contact the inner peripheral wall of the stator 2. When the air gap is normal, since the positioning ring 3 is fixed, the four measuring pieces 4 will not shift in angle and will move in a straight line. Therefore, after the measurement is completed, it is always the probe in the middle that contacts the inner peripheral wall of the stator 2, and the probes 5 at other positions on the measuring piece 4 will not obtain measurement data. For example Figure 13 the relative positional relationship between the measuring piece 4 and the probe 5 in the first detection area and the stator 2; particularly, when the number of probes 5 is dense, the probes 5 adjacent to the middle probe 5 will also collect data; the linear distance from the middle probe 5 to the center of the positioning ring should be equal to l D and will not deviate from the center of the second image generated with l D as the radius

[0069] After measuring the angle of this area, the positioning ring 3 can be rotated to change the position of the measuring piece 4 and measure the data information of other detection areas or adjacent detection areas

[0070] Taking the example of an abnormal air gap again, the change in the distance of the air gap is related to both the stator 2 and the rotor 1 If there is a problem with the rotor 1, such as local bulging, etc., after the measuring ring 31 is sleeved on the rotor 1, the measuring piece 4 attached to the bulging part will surely tilt, and the distance from each probe 5 at this measuring piece 4 to the center of the positioning ring 3 l T will all be different, and among the ones used for positioning 、 and there will be one or more straight lines deviating from the center of the first image generated by the central processing unit; after the installation is completed, when it is known that any straight line of the probe 5 deviates from the first image, it means that there is a problem with the rotor 1 at that place. At the same time, according to the l T of this measuring probe 5 and lZ By comparison, the degree of bulging can be determined, and based on the corresponding results, it can be determined whether it is necessary to continue measuring or to perform repairs in a timely manner.

[0071] In addition, the rotor 1 may have an eccentricity problem, that is, the rotor 1 and the stator 2 are not coaxial. The measuring piece 4 in the present invention is mounted on the rotor 1 for measurement. After installation, if there is no quality or surface problem with the rotor 1, the straight-line distance from the probe 5 of the measuring piece 4 to the center of the positioning ring 3 in the four detection areas is l T It should be consistent with the first image, and the two are consistent in a normal state. At this time, the measurement step will continue to be executed, and after the probes 5 of the four measuring pieces 4 contact the stator 2, the air gap distances h of the four detection areas are calculated.

[0072] The above-mentioned problem of eccentricity of the rotor 1 will be further illustrated by an example. If the rotor 1 deviates toward the upper right of the stator 2, the air gap distance h1 of the first detection area is the smallest relative to the other three detection areas. Correspondingly, the air gap distance h3 of the third detection area is the largest. Similarly, the four measuring pieces 4 used for positioning , and will also deviate from the predetermined second image and will not l D equal length; this proves that rotor 1 has an eccentricity problem.

[0073] Similarly, if no problem occurs before the measurement, but during or after the measurement, the probe in the middle of the measuring piece 4 does not obtain any information, while the probe 5 at the head end, tail end or adjacent to the head and tail ends of the measuring piece 4 obtains position data information, then it is proved that a bulge has appeared on the stator 2 at that location and it has been contacted by the probe 5 of the measuring piece 4 in advance. In addition, after the probe in the middle obtains data information, the probe 5 at the head and tail ends or adjacent to the head and tail ends, which should not have obtained information, also obtains data information, then it is also proved that there is a problem with the stator 2.

[0074] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A measuring device for the air gap between the stator and rotor of a generator, characterized in that Comprising: A positioning ring (3), one end of the positioning ring (3) is provided with a detection component; A plurality of probes (5) distributed in an annular array are arranged on the outer peripheral wall of the detection component, a displacement sensor is arranged in the probe (5), and a plurality of the displacement sensors are signal-connected to a central processing unit; A measuring component, the measuring component is arranged on the rotating shaft of the generator; Wherein, the positioning ring (3) is used to be sleeved on the outer peripheral wall of the rotor (1), so that the positioning ring (3) and the detection component are located in the air gap, the measuring component is used to push the detection component, so that the detection component abuts against the stator (2), and the displacement sensor is used to record the displacement data of the probe (5) and feedback it to the central processing unit.

2. The measuring device for the air gap between the stator and rotor of a generator according to claim 1, characterized in that: The detection component is a measuring ring (31), the measuring ring (31) and the positioning ring (3) are coaxially arranged, the diameter of the measuring ring (31) is larger than the diameter of the positioning ring (3), the measuring ring (31) and the positioning ring (3) are fixedly connected, and the measuring component is a pushing shaft (62), and the diameter of the pushing shaft (62) is larger than the diameter of the measuring ring (31).

3. The measuring device for the air gap between the stator and rotor of a generator according to claim 1, wherein: The detection component is a plurality of measuring pieces (4), the measuring pieces (4) are arc-shaped and are distributed in an annular array along the center of the positioning ring (3) and are coaxially arranged with the positioning ring (3), the probes (5) are annularly and evenly distributed on the outer peripheral wall of the measuring pieces (4), the measuring component is a pushing member (6), and when the pushing member (6) moves along the measuring pieces (4), the distances from a plurality of the measuring pieces (4) to the center of the positioning ring (3) increase synchronously.

4. The measuring device for the air gap between the stator and rotor of a generator according to claim 3, characterized in that: An annular groove is formed on the outer peripheral wall of the positioning ring (3) on the side close to the measuring piece (4), a limiting block (41) is fixedly connected to the measuring piece (4), one end of the measuring piece (4) is located on the annular groove, the other end of the measuring piece (4) is located outside, a plurality of first springs (71) connected to the measuring piece (4) are arranged on the annular groove, the pushing member (6) has a frustum-shaped structure, the end with the smallest diameter of the pushing member (6) faces the positioning ring (3), and the side of the limiting block (41) facing the center of the positioning ring (3) is an inclined surface.

5. The measuring device for the air gap between the stator and rotor of a generator according to claim 3, characterized in that: A plurality of grooves are formed on one end surface of the positioning ring (3), connecting holes are formed on both side surfaces of the grooves, a plurality of hinge blocks (42) corresponding to the grooves are fixedly connected to the side of the measuring piece (4) facing the positioning ring (3), connecting shafts rotatably connected to the connecting holes are respectively arranged at both ends of the hinge block (42), the pushing member (6) has a cylindrical structure, a plurality of push rods (61) abutting against the measuring piece (4) are arranged on the outer peripheral wall of the pushing member (6), a second spring (72) connected to the pushing member (6) is arranged at the bottom end of the push rod (61), and the top end of the push rod (61) is an inclined surface.

6. The measuring device for the air gap between the stator and rotor of a generator according to claim 3, characterized in that: Taking the center of the rotor (1) as the center, the positioning ring (3) is equally divided into four detection areas, and one measuring piece (4) is arranged in each detection area.

7. The measuring device for the air gap between the stator and rotor of a generator according to claim 6, characterized in that: A probe (5) is provided on the measuring piece (4) of each of the detection areas. When the probe (5) abuts against the inner peripheral wall of the stator (2) in the detection area, a detection radius is obtained, and the air gap is calculated using the detection radius.

8. The measuring device for the air gap between the stator and rotor of a generator according to claim 6, characterized in that: The probe (5) of each measurement piece (4) is represented by the distance from the current point to the center of the positioning ring (3) as l T , the distance from the center of the rotor (1) to the probe (3) is l Z , the distance from the center of the rotor (1) to the inner peripheral wall of the stator (2) is l D ; The central processing unit, according to l Z draws a first image by making a circle with l D as the radius, draws a second image by making a circle with l T as the radius, and compares them with the first image and the second image before and after measurement respectively.

9. A method for measuring the air gap between the stator and rotor of a generator, which measures the air gap according to a measuring device for the air gap between the stator and rotor of a generator as described in claims 6-8, characterized in that, The measurement is carried out through the following steps: Step 1, preparation before measurement; Step 2, install the positioning ring (3) and the detection component, and start the central processing unit. Divide the positioning ring into four detection areas with the center of the rotor as the center. Step 3, measure and record the initial data of the probe (5), and feed the data back to the central processing unit for comparison. Step 4, control the detection component to move towards the stator (2), record the final data of the probe (5), and feed the data back to the central processing unit for comparison. Step 5, generate a report on the comparison results of steps 3 and 4.

10. A method for measuring the air gap between the stator and rotor of a generator according to claim 9, characterized in that: The said step 2 includes: Step 21, installation of the positioning ring (3): sleeved the positioning ring (3) on the rotor (1), keep the two coaxial, and install the detection component on the positioning ring (3). Step 22, preliminary inspection: check whether the detection component is in the initial state and check whether the probe (5) is damaged. The said step 3 includes: Step 31, generation of initial data: before the probe (5) moves, the displacement sensor records and generates the position of the probe (5), and feeds the data back to the central processing unit. Step 32, data comparison before measurement: when the straight line from the probe (5) to the center of the positioning ring (3) in any detection area deviates from the first image, record this detection area.

11. A method for measuring the air gap between the stator and rotor of a generator according to claim 10, characterized in that: The said step 32 includes: Step 321, the central processing unit draws a first image by making a circle with the distance from the center of the rotor to the probe as the radius l Z ; Step 322, respectively compare the straight lines from the probes (5) to the center of the positioning ring (3) in the four detection areas with the first image, and record the comparison results.

12. The measuring method for the air gap between the stator and rotor of a generator according to claim 9, wherein: The said step 4 includes: Step 41, move the detection component to the inner peripheral wall of the stator (2): control the pushing member (6) to push the detection component to move towards the inner peripheral wall of the stator (2) until it abuts. Step 42, the displacement sensor records the data of each probe (5) after abutting against the inner peripheral wall of the stator (2), and feeds it back to the central processing unit. Step 43, data comparison after measurement: obtain the air gap distance.

13. A method for measuring the air gap between the stator and rotor of a generator according to claim 12, characterized in that: The said step 43 includes: Step 431: Measure the distance from the center of the rotor (1) to the inner peripheral wall of the stator (2). l D ; Based on l D as the radius, draw a second image as a circle. Step 432, obtain the straight lines from the probes (5) in the middle parts of the four measuring pieces (4) to the center of the positioning ring (3). Step 433, respectively compare the straight lines from the probes (5) in the middle parts of the four detection areas after measurement to the center of the positioning ring (3) with the second image, and record the comparison results.

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