CN106643906A - Monitoring method and monitoring system for variable-pitch bearing - Google Patents

Abstract

The invention relates to a monitoring method and a monitoring system for a variable-pitch bearing. Pitch bearing (100) comprises a bearing end face (130, 140) and bolt holes (1-54) formed in the bearing end face (130, 140), and is characterized in that the monitoring method comprises the following steps: monitoring temperature parameters and strain parameters of the bearing end surfaces (130, 140) or the bolt holes (1-54) by using a fiber bragg grating sensing measurement system (500); and correcting the strain parameters of the bearing end surfaces (130, 140) or the bolt holes (1-54) by using the temperature parameters to obtain actual strain parameters.

Description

Monitoring method and monitoring system for pitch bearing

technical field

The invention relates to the technical field of monitoring bearings, in particular to a monitoring method and a monitoring system for variable pitch bearings.

Background technique

Energy is the main material basis of social economy and human life, and the driving force of social development. However, the reserves of non-renewable energy such as petroleum, coal, and natural gas, which are the main pillars of energy in the world, are decreasing day by day. All countries in the world are developing wind power generation. As a new energy source, wind power generation has formed a mature scale.

A wind turbine is a device that converts wind energy into electrical energy. In a wind turbine, the pitch bearing, as the connecting part between the blade and the hub, plays a very important role in the pitch change process of wind power generation. Pitch adjustment is to change the angle of attack of the airflow on the blades by adjusting the angle of the blades, thereby changing the aerodynamic force obtained by the wind turbine, so that the wind turbine can output according to the designed output power. Due to the large weight and aerodynamic thrust of the blades, the pitch bearing is subject to a large load, especially the end face of the pitch bearing and the bolt holes used for connection, which may crack due to excessive load. Moreover, the working environment of the pitch bearing is harsh, and the ambient temperature gradient is large, and the pitch bearing may also cause failure due to changes in temperature affecting the lubrication of the grease and the characteristics of the material. Due to the complex structural stress of the pitch bearing and the uneven distribution of the working temperature field, monitoring means are very important in order to give early warning and reduce quality and safety accidents.

Contents of the invention

In the past, the technical means for monitoring bearings were insufficient, and the force characteristics of bearings could not be fully considered. The current method is to use the resistance strain gauge to install and measure the possible stress concentration points, but because the installation space of the stress concentration area of the bearing itself and the measured surface are small, and the resistance strain gauge measurement is only a single-point stress measurement, if you want to describe Linear stress and surface stress require the installation of a large number of resistance strain gauges, lead wires, and acquisition equipment channels, which are costly, difficult to operate, and have a short service life. In addition, the strong magnetic field in the working environment of the pitch bearing has a greater impact on the monitoring results. In addition, if the temperature field distribution of the entire bearing is to be measured, additional temperature sensors, wiring and acquisition equipment need to be installed.

The purpose of the present invention is to provide a monitoring method and monitoring system for a pitch bearing, which can avoid electromagnetic interference, prolong the service life, simplify installation and wiring, and reduce the monitoring cost of the pitch bearing.

One aspect of the present invention provides a monitoring method for a pitch bearing, the pitch bearing includes a bearing end face and bolt holes opened on the bearing end face, the monitoring method includes: using a fiber grating sensing measurement system monitoring the temperature parameter and the strain parameter of the bearing end surface or the bolt hole; and using the temperature parameter to correct the strain parameter of the bearing end surface or the bolt hole to obtain an actual strain parameter.

Another aspect of the present invention provides a monitoring system for a pitch bearing. The pitch bearing includes a bearing end face and bolt holes opened on the bearing end face. The monitoring system includes: an optical fiber grating sensing and measuring system for measuring monitoring the temperature parameters and strain parameters of the bearing end face or the bolt holes; and a correction unit, using the temperature parameters to correct the strain parameters of the bearing end face or the bolt holes to obtain actual strain parameters.

According to the above-mentioned monitoring method and monitoring system of the pitch bearing, the optical fiber grating sensing measurement system is used to replace the previous resistance strain gauge. Since pitch bearings are sometimes in high humidity, smog, or lightning working environments, the fiber grating sensor is made of optical fiber, which has good insulation performance, corrosion resistance, and stable chemical properties. The optical signal is not affected by electromagnetic interference, and can be used stably in the working environment of high humidity, smog, lightning or electromagnetic interference. Therefore, electromagnetic interference can be avoided, the service life is prolonged, and installation and wiring are simple. In addition, the optical fiber grating sensor can form the shape corresponding to the selected parts such as the end face of the pitch bearing outer ring, the end face of the inner ring, the circumferential surface of the outer ring or the bolt holes through bare grating covering, micro-sensor welding, etc., so the installation difficulty and installation The cost is lower.

According to the above-mentioned monitoring method and monitoring system of the pitch bearing, the strain and temperature of the bearing end face are monitored using the fiber grating sensing measurement system, and the strain and the temperature of the bearing end face are monitored according to the strain of the bearing end face and the pre-established strain of the bearing end face and the strain of the bolt hole. relation to obtain the strain in the bolt hole. That is, it is only necessary to install a fiber optic grating sensor on the bearing end surface of the pitch bearing, and according to the predetermined corresponding relationship between the strain of the bearing end surface of the pitch bearing and the strain of the bolt hole of the pitch bearing, the bolt hole of the pitch bearing can be obtained The strain of the pitch bearing does not need to install the fiber grating sensor in both the bearing end face and the bolt hole of the pitch bearing, thereby reducing the monitoring cost of the bearing end face and the bolt hole of the pitch bearing. In addition, according to the strain of the bearing end surface of the pitch bearing and the predetermined corresponding relationship between the strain of the bearing end surface of the pitch bearing and the strain of the bolt hole of the pitch bearing, a more accurate strain of the bolt hole can be obtained, thereby eliminating the need to The sensor is installed in the bolt hole, and the bolt can be placed in the bolt hole, which ensures the service life of the pitch bearing. Therefore, while ensuring the service life of the pitch bearing, more accurate monitoring results of the strain in the bolt holes can be obtained. Alternatively, the strain and temperature of the bolt holes are monitored using a fiber Bragg grating sensing measurement system, and the strain of the bearing end surface is obtained according to the strain of the bolt holes and the pre-established relationship between the strain of the bearing end surface and the strain of the bolt hole. That is, similarly, it is only necessary to install a fiber grating sensor in the bolt hole of the pitch bearing, and according to the predetermined corresponding relationship between the strain of the bearing end face of the pitch bearing and the strain of the bolt hole of the pitch bearing, the pitch bearing The strain of the end face and the bolt hole of the pitch bearing does not need to install the fiber grating sensor in both the bearing end face and the bolt hole of the pitch bearing, thereby reducing the monitoring cost of the bearing end face and the bolt hole of the pitch bearing.

According to the above monitoring method and monitoring system for pitch bearings, fiber grating sensors are installed at 0°, 90°, 180° and 270° of the circumference of the bearing end face, that is, the fiber grating sensors are arranged in a ring arrangement. Through the above-mentioned arrangement of the fiber grating sensor, the line or surface stress and the temperature field of the pitch bearing can be accurately evaluated, the design parameters are optimized, and the failure probability is reduced.

According to the above-mentioned monitoring method and monitoring system for a pitch bearing, a plurality of measuring points are set at 0° and 180° of the circumference of the end face of the bearing to install the fiber grating sensor. Since the loads carried at 0° and 180° on the bearing end face of the pitch bearing are relatively large, multi-point measurements are concentrated here, so that the stress state here can be measured more accurately.

According to the above-mentioned monitoring method and monitoring system for a pitch bearing, the fiber grating sensor is installed axially or radially on the inner wall of the bolt hole. Since the inner wall cracks of the bolt holes of the pitch bearing are more likely to be damaged in the axial or radial direction, the fiber grating sensors are arranged in the axial or radial direction, so that the stress state of the bolt holes can be measured more accurately.

According to the above-mentioned monitoring method and monitoring system for the pitch bearing, the fiber grating sensor is connected to the optical demodulator through the optical fiber link, and the two ends of the optical fiber link are respectively connected to the optical demodulator. In this way, data can be collected synchronously, and communication fault redundancy design can be achieved. Even if a fault occurs somewhere in the middle of the optical path, it will not affect the communication test of the entire optical path.

Description of drawings

The features, advantages, and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a front view showing the structure of a pitch bearing according to the present invention;

Fig. 2 is a structural diagram showing the fiber grating sensing measurement system involved in the present invention;

Fig. 3 is a flow chart showing one of the monitoring methods of the pitch bearing involved in the present invention;

Fig. 4 is a flow chart showing the second monitoring method of the pitch bearing involved in the present invention;

Fig. 5 exemplifies the corresponding relationship between the strain of the end surface of the outer ring of the pitch bearing and the strain of the bolt hole;

Fig. 6 is a configuration diagram showing a monitoring system of a pitch bearing according to the present invention.

In the figures, the same parts are given the same reference numerals. The figures are not drawn to scale.

Label description

100 pitch bearing; 110 bearing outer ring; 120 bearing inner ring; 130 outer ring end face; 140 inner ring end face; 1~54 bolt holes; 200 fiber grating strain and temperature sensor; 300 optical fiber link; 500 fiber grating sensing measurement system; 500a correction unit; 600 acquisition unit; 700 early warning unit; 800 monitoring system

detailed description

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings and examples. The detailed description and drawings of the following embodiments are used to illustrate the principle of the present invention, but not to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

In the description of the present invention, it should be noted that unless otherwise specified, the meaning of "several" is one or more; the meaning of "plurality" is two or more; the terms "upper" and "lower" , "Left", "Right", "Inner", "Outer", "Front", "Rear", "Head", "Tail" and other indicated directions or positional relationships are based on the directions shown in the drawings or The positional relationship is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

As the connecting part between the blade and the hub, the pitch bearing is an important part of the pitch system of the wind turbine, and its structure is divided into two types: internal tooth type and external tooth type. The so-called internal tooth type refers to the meshing of the inner ring of the bearing with teeth and the pinion of the drive motor. The connection method is that the inner ring is connected to the blade through bolts, and the outer ring is connected to the hub through bolts; The drive motor pinion meshes, and the connection method is that the outer ring is connected to the blade through bolts, and the inner ring is connected to the hub through bolts. Hereinafter, the present embodiment will be described as an example of an external gear pitch bearing.

FIG. 1 is a front view showing the structure of a pitch bearing according to the present invention. As shown in Figure 1, the pitch bearing 100 includes a bearing outer ring 110, a bearing inner ring 120, and bolt holes for connecting the blades and the hub that are opened on the end face 130 of the outer ring and the end face 140 of the inner ring. 54 bolt holes are marked clockwise with numbers 1, 2, 3...54. The bearing outer ring 110 is connected to the blade (not shown) through bolts, and the bearing inner ring 120 is connected to the hub (not shown) through bolts. The bearing outer ring 110 can rotate relative to the bearing inner ring 120, thereby changing the windward angle of the blade and keeping the blade in an optimal windward state. The internal structure of the pitch bearing includes double-row ball bearings, etc. The pitch bearing can not only bear radial loads, but also has a certain bearing capacity for axial loads.

As mentioned above, in the wind power generator, the pitch bearing plays a very important role in the pitching process of wind power generation. Pitch adjustment is to change the angle of attack of the airflow on the blades by adjusting the angle of the blades, thereby changing the aerodynamic force obtained by the wind turbine, so that the wind turbine can output according to the designed output power. Due to the large weight and aerodynamic thrust of the blades, the pitch bearing is subject to a large load, especially the end face of the pitch bearing and the bolt holes used for connection, which may crack due to excessive load. Moreover, the working environment of the pitch bearing is harsh, and the ambient temperature gradient is large, and the pitch bearing may also cause failure due to changes in temperature affecting the lubrication of the grease and the characteristics of the material. Due to the complex structural stress of the pitch bearing and the uneven distribution of the working temperature field, monitoring means are very important in order to give early warning and reduce quality and safety accidents.

For this reason, the inventors of the present invention have devoted themselves to researching a monitoring method, installing optical fiber grating sensors on the pitch bearing outer ring end face, inner ring end face, bearing outer ring circumferential surface or bolt holes to replace the previous resistors. Strain gauges are used to monitor the pitch bearing outer ring end face, inner ring end face, bearing outer ring circumferential surface or bolt holes such as strain, temperature parameters, etc., according to the pitch bearing outer ring end face, inner ring end face of the pitch bearing , the strain parameters of the outer ring circumference of the bearing and the bolt holes to give an early warning to prevent the pitch bearing from being damaged during operation. That is, the monitoring objects of the present invention are the end face of the pitch bearing outer ring, the end face of the inner ring, the circumferential surface of the outer ring of the bearing and the inner wall of the bolt hole of the connecting bolt, thus covering all areas of the bearing. In the case of distinction, sometimes the end face of the outer ring of the pitch bearing, the end face of the inner ring, and the circumferential surface of the outer ring of the bearing are collectively referred to as the bearing end face of the pitch bearing. Since there is a certain connection between the bearing end surface of the pitch bearing and the strain parameters of the bolt holes, the corresponding relationship between the strain parameters of the bearing end surface of the pitch bearing and the strain parameters of the bolt holes can be established in advance, and the details will be described later.

As shown in Figure 1, a fiber grating strain and temperature sensor 200 is arranged on the outer ring end face 130 of the pitch bearing 100, and the fiber grating strain and temperature sensor 200 collects such as strain and temperature parameters of the outer ring end face 130 of the pitch bearing 100 light signal. Specifically, a measuring point is installed at 0°, 90°, 180° and 270° on the outer ring end face 130 of the pitch bearing 100 to install a fiber grating strain and temperature sensor 200 for collecting the temperature of the pitch bearing 100. Optical signals of strain and temperature of the outer ring end face 130 . In FIG. 1 , according to the shape of the blade, 0° of the outer ring end surface 130 is the trailing edge position of the blade, and 180° of the outer ring end surface 130 is the leading edge position of the blade. Further, since the 0° and 180° positions on the outer ring end surface 130 of the pitch bearing 100 carry relatively large loads, multiple The measuring points are concentrated to install the FBG strain and temperature sensors 200, for example, 6 measuring points are set at 0° to install the FBG strain and temperature sensors 200. The optical fiber grating strain and temperature sensor 200 forms a shape corresponding to selected parts such as the end face of the pitch bearing outer ring by covering the bare grating and welding the micro sensor.

FIG. 2 is a configuration diagram showing a fiber grating sensing measurement system 500 according to the present invention. As shown in FIG. 2 , the fiber grating strain and temperature sensor 200 is connected to the optical demodulator 400 through the optical fiber link 300 , and the two ends of the optical fiber link 300 are respectively connected to the optical demodulator 400 . The optical demodulator 400 analyzes the optical signal collected by the FBG strain and temperature sensor 200 to measure the strain and temperature of the end face 130 of the outer ring of the pitch bearing 100 . The fiber grating strain and temperature sensor 200 , the fiber link 300 and the optical demodulator 400 constitute a fiber grating sensing measurement system 500 .

Since the test results of fiber grating strain sensors are greatly affected by temperature, temperature compensation is required.

The strain and temperature compensation calculation methods are as follows.

Take one of the fiber grating strain sensors as an example to calculate its strain, the initial center wavelength of the sensor: λ0 (nm) (measured at room temperature, when the sensor is in a free state);

After pre-installed on the end face 130 of the outer ring, the wavelength is calibrated: λS0 (in nm, measured at 25°C). After the sensor is installed on the end face 130 of the outer ring, the central wavelength of the sensor changes. After the sensor is installed, the temperature T1 can be measured on site and wavelength λ1 and then through the expression

λS0=λ1-(T1-25)*C _S is obtained,

Read wavelength during actual measurement after strain generation: λ _S1 (nm) (measured at room temperature)

Wavelength change: Δλ=λ _s1 -λs0

Fiber Bragg grating strain sensor strain sensitivity: F _S (με/pm)

Temperature Coefficient of Fiber Bragg Grating Strain Sensor: C _S (°C/pm)

Calculation formula of strain (με) generated during work:

Δε＝(Δλ-ΔT*C _S )*F _S

in,

ΔT can be measured by a fiber grating temperature sensor, and its calculation expression is:

ΔT=(λ _T1 -λ _T0 )/C _T

The reading wavelength of the fiber grating temperature sensor in actual measurement: λ _T1 (nm)

Fiber Bragg Grating temperature sensor initial wavelength: λ _T0 (nm, measured at room temperature)

Sensitivity coefficient of fiber grating temperature sensor: C _T

Stress calculation method:

The calculation expression of stress σ is:

σ=Δε*E

Where △ε is the amount of strain change, and E is the elastic modulus of the material of the pitch bearing outer ring.

Similarly, the stress measured by other FBG strain sensors can be obtained by the above method. Through the above temperature compensation, the actual stress state of the outer ring end surface 130 of the pitch bearing can be obtained.

As mentioned above, since there is a certain relationship between the bearing end surface of the pitch bearing and the strain parameters of the bolt holes, the corresponding relationship between the strain parameters of the bearing end surface of the pitch bearing and the strain parameters of the bolt holes can be established in advance. Here, the corresponding relationship between the strain parameters of the end surface of the outer ring of the pitch bearing and the strain parameters of the bolt holes can be obtained in advance according to experiments. FIG. 5 shows an example of the correspondence relationship between the strain on the end surface of the outer ring of the pitch bearing and the strain on the bolt holes. Wherein, the X-axis represents the strain of the outer ring end surface 130 of the pitch bearing 100, the Y-axis represents the strain of the bolt hole, and R2 is a correlation coefficient, and the closer to 1, the higher the correlation between the ^two . Here, since a measuring point is set at 0°, 90°, 180° and 270° on the end surface 130 of the outer ring of the pitch bearing 100, the serial numbers of the corresponding bolt holes are 1, 14, 28, 41 .

Next, the monitoring method of the pitch bearing according to the present invention will be specifically described. FIG. 3 is a flowchart showing one of the monitoring methods of the pitch bearing according to the present invention. In step 101 , the corresponding relationship between the strain of the outer ring end surface 130 of the pitch bearing 100 and the strain of the bolt holes is obtained in advance according to experiments. In step 102, the optical signals of temperature and strain of the outer ring end face 130 of the pitch bearing 100 are collected using the optical fiber grating strain and temperature sensor 200, and the optical signals collected by the optical fiber grating strain and temperature sensor 200 are analyzed by the optical demodulator 400 For analysis, the temperature and strain of the outer ring end surface 130 of the pitch bearing 100 are measured. In step 103 , the temperature of the end surface 130 of the outer ring is used to correct the strain of the end surface 130 of the outer ring to obtain the actual strain of the end surface 130 of the outer ring. In step 104, the strain of the bolt hole is obtained according to the actual strain of the end surface 130 of the outer ring and the corresponding relationship between the strain of the end surface 130 of the outer ring of the pitch bearing 100 and the strain of the bolt hole. In step 105, the strain of the end surface 130 of the outer ring of the pitch bearing 100 and the strain of the bolt holes obtained above are compared with a preset fault strain threshold, and an early warning is issued according to the comparison result.

In the above monitoring method, the strain and temperature of the outer ring end face 130 of the pitch bearing 100 are measured by using the fiber Bragg grating sensing measurement system 500. According to the measured strain and the outer ring end face 130 of the pitch bearing 100 The strain of the bolt hole can be obtained by the corresponding relationship between the strain of the bolt hole and the strain of the bolt hole, but the monitoring method involved in the present invention is not limited thereto, and the strain and temperature of the bolt hole can also be measured using the fiber grating sensing measurement system 500, according to the measured The strain of the bolt holes and the corresponding relationship between the strain of the outer ring end surface 130 of the pitch bearing 100 and the strain of the bolt holes are used to obtain the strain of the outer ring end surface 130 of the pitch bearing 100 .

Specifically, in the bolt holes 1, 14, 28, and 41 at 0°, 90°, 180°, and 270° of the pitch bearing 100, a measuring point is installed to install a fiber grating strain and temperature sensor 200, and The inner walls of the holes 1, 14, 28, 41 are installed with fiber grating strain and temperature sensors 200 axially or radially. Fig. 4 is a flow chart showing the second monitoring method of the pitch bearing involved in the present invention. In step 201 , the corresponding relationship between the strain of the outer ring end surface 130 of the pitch bearing 100 and the strain of the bolt holes is obtained in advance according to experiments. In step 202, the strain and temperature optical signals of the bolt holes of the pitch bearing 130 are collected using the optical fiber grating strain and temperature sensor 200, and the optical signals collected by the optical fiber grating strain and temperature sensor 200 are analyzed by the optical demodulator 400 , the strain and temperature of the bolt holes of the pitch bearing are measured. In step 203, the temperature of the bolt hole is used to correct the strain of the bolt hole to obtain the actual strain of the bolt hole. In step 204 , the strain of the outer ring end surface 130 of the pitch bearing 100 is obtained according to the actual strain of the bolt hole and the corresponding relationship between the strain of the outer ring end surface 130 of the pitch bearing 100 and the strain of the bolt hole. In step 205, the strain of the bolt holes of the pitch bearing 100 obtained above and the strain of the end face 130 of the outer ring are compared with a preset fault strain threshold, and an early warning is issued according to the comparison result.

In the monitoring method of the pitch bearing 100 involved in this embodiment, the optical fiber grating sensing measurement system 500 is used instead of the conventional resistance strain gauge. Since pitch bearings are sometimes in high humidity, smog, or lightning working environments, the fiber grating sensor is made of optical fiber, which has good insulation performance, corrosion resistance, and stable chemical properties. The optical signal is not affected by electromagnetic interference, and can be used stably in the working environment of high humidity, smog, lightning or electromagnetic interference. Therefore, electromagnetic interference can be avoided, the service life is prolonged, and installation and wiring are simple. In addition, the optical fiber grating sensor can form the shape corresponding to the selected parts such as the end face of the pitch bearing outer ring, the end face of the inner ring, the circumferential surface of the outer ring or the bolt holes through bare grating covering, micro-sensor welding, etc., so the installation difficulty and installation The cost is lower.

In addition, to monitor the strain in the bolt hole, a sensor needs to be installed in the bolt hole. In order to ensure that the sensor is not damaged, no bolts can be placed in the bolt holes where the sensors are installed, but the bolt holes without bolts will be easily damaged due to the large load during the operation of the pitch bearing, thereby reducing the pitch bearing. service life. If you want to get a more accurate strain of the bolt holes, you need to install sensors in multiple bolt holes, but since no bolts can be placed in the bolt holes where the sensors are installed, it will bring hidden dangers to the safety of the fan operation. If you want to ensure the safe operation of the unit, you cannot get a more accurate strain of the bolt hole. In view of the above, in the monitoring method of the pitch bearing 100 involved in this embodiment, the strain and temperature of the end face 130 of the bearing outer ring are monitored using the fiber grating sensing measurement system 500, and according to the strain of the end face 130 of the outer ring and the pre-established The strain of the bolt hole is obtained by the corresponding relationship between the strain of the outer ring end face 130 and the strain of the bolt hole. That is, it is only necessary to install the fiber grating strain and temperature sensor 200 on the end surface 130 of the bearing outer ring of the pitch bearing 100, and according to the predetermined correspondence between the strain of the end surface 130 of the bearing outer ring of the pitch bearing and the strain of the bolt hole of the pitch bearing relationship, the strain of the bolt hole of the pitch bearing 100 can be obtained without installing the fiber grating strain and temperature sensor 200 in both the end face 130 of the bearing outer ring of the pitch bearing 100 and the bolt hole, thereby reducing the strain of the pitch bearing 100 The cost of monitoring the bearing outer ring face 130 and bolt holes. In addition, according to the measured strain of the end surface 130 of the bearing outer ring of the pitch bearing 100 and the predetermined corresponding relationship between the strain of the end surface 130 of the bearing outer ring of the pitch bearing 100 and the strain of the bolt holes of the pitch bearing 100, a comparative The strain of the bolt hole is accurate, so there is no need to install a sensor in the bolt hole, and bolts can be placed in the bolt hole, which ensures the service life of the pitch bearing 100 . Therefore, while ensuring the service life of the pitch bearing 100 , more accurate monitoring results of the strain in the bolt holes can be obtained.

Alternatively, in the monitoring method of the pitch bearing involved in this embodiment, the strain and temperature of the bolt holes are monitored using the fiber grating sensing measurement system 500, and according to the strain of the bolt holes and the pre-established strain of the end surface 130 of the bearing outer ring The strain of the end face 130 of the bearing outer ring is obtained from the corresponding relationship with the strain of the bolt hole. That is, similarly, it is only necessary to install the fiber grating strain and temperature sensor 200 in the bolt hole of the pitch bearing 100, according to the strain of the end surface 130 of the bearing outer ring of the pitch bearing 100 and the strain of the bolt hole of the pitch bearing 100 Corresponding relationship, the strain of the outer ring end surface 130 of the pitch bearing 100 can be obtained, without the need to install fiber grating strain and temperature sensors 200 in both the bearing outer ring end surface 130 and the bolt holes of the pitch bearing 100, thereby reducing the strain The cost of monitoring the bearing outer ring end face 130 and the bolt holes of the paddle bearing 100 .

In addition, in the monitoring method of the pitch bearing 100 involved in this embodiment, fiber grating strain and temperature sensors 200 are installed at 0°, 90°, 180° and 270° of the circumference of the end face 130 of the bearing outer ring, that is, a ring arrangement is adopted The fiber grating strain and temperature sensor 200 is arranged in a different manner. Through the above-mentioned arrangement of the fiber grating strain and temperature sensors 200, the line or surface stress and the temperature field of the pitch bearing 100 can be accurately evaluated, the design parameters are optimized, and the failure probability is reduced. In addition, the arrangement point of the fiber grating strain and temperature sensor 200 is not limited to this, and the fiber grating can also be installed at 0°, 45°, 90°, 135°, 180°, 225° and 270° of the end face 130 of the bearing outer ring Strain and temperature sensors 200 , thereby enabling a more accurate assessment of the linear or surface stress and temperature field of the pitch bearing 100 .

In addition, in the monitoring method of the pitch bearing 100 involved in this embodiment, a plurality of measuring points are installed at 0° and 180° of the end face 130 of the bearing outer ring to install the fiber grating strain and temperature sensors 200 . Since the loads carried at 0° and 180° on the end surface 130 of the bearing outer ring of the pitch bearing 100 are relatively large, multi-point measurements are concentrated here, so that the stress state here can be measured more accurately.

In addition, in the monitoring method of the pitch bearing 100 involved in this embodiment, the fiber grating strain and temperature sensor 200 is installed axially or radially on the inner wall of the bolt hole. Since cracks on the inner wall of the bolt holes of the pitch bearing 100 are more likely to be damaged axially or radially, the fiber grating strain and temperature sensors 200 are arranged axially or radially, so that the stress state of the bolt holes can be measured more accurately .

In addition, in the monitoring method of the pitch bearing 100 involved in this embodiment, the fiber grating strain and temperature sensor 200 is connected to the optical demodulator 400 through the optical fiber link 300, and the two ends of the optical fiber link 300 are connected to the optical demodulator 400 respectively. 400 connections. In this way, data can be collected synchronously, and communication fault redundancy design can be achieved. Even if a fault occurs somewhere in the middle of the optical path, it will not affect the communication test of the entire optical path.

Above, the technical solution of the present invention is realized through the monitoring method of the pitch bearing, but the technical solution of the present invention can also be realized through the monitoring system of the pitch bearing. Fig. 6 is a configuration diagram showing a monitoring system of a pitch bearing according to the present invention. As shown in FIG. 6 , the monitoring system 800 of the pitch bearing involved in the present invention includes: an optical fiber grating sensing and measuring system 500, and the optical fiber grating sensing and measuring system 500 measures the temperature parameters and Strain parameters are monitored; the correction unit 500a uses the temperature parameters to correct the strain parameters of the bearing end surface or the bolt holes to obtain actual strain parameters; the acquisition unit 600, the acquisition unit 600 pre-establishes the bearing The corresponding relationship between the strain parameter of the end surface and the strain parameter of the bolt hole, and according to the actual strain parameter of the bearing end surface or the actual strain parameter of the bolt hole and the pre-established strain parameter of the bearing end surface and the bolt The strain parameter of the bolt hole or the strain parameter of the bearing end surface is obtained through the corresponding relationship of the strain parameter of the hole; the early warning unit 700, the early warning unit 700 compares the strain parameter with a predetermined fault strain parameter threshold, according to The comparison results are alerted. Therefore, the monitoring system 800 adopting the above-mentioned pitch bearing can also obtain the above-mentioned technical effect.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for parts thereof without departing from the scope of the invention. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims (11)

1. A monitoring method for a pitch bearing (100), the pitch bearing (100) comprising a bearing end face (130, 140) and bolt holes (1-140) provided on the bearing end face (130, 140) 54), it is characterized in that, described monitoring method comprises: monitoring temperature parameters and strain parameters of the bearing end faces (130, 140) or the bolt holes (1-54) by using a fiber Bragg grating sensing measurement system (500); and The temperature parameters are used to correct the strain parameters of the bearing end surfaces (130, 140) or the bolt holes (1-54), so as to obtain actual strain parameters. 2. The monitoring method according to claim 1, wherein the monitoring method specifically comprises: The corresponding relationship between the strain parameters of the bearing end faces (130, 140) and the strain parameters of the bolt holes (1-54) is established in advance, and the fiber grating sensing and measuring system (500) is used to measure the bearing end faces (130 , 140) temperature parameters and strain parameters are monitored; correcting the strain parameter of the bearing end face (130, 140) by using the temperature parameter of the bearing end face (130, 140), so as to obtain the actual strain parameter of the bearing end face (130, 140); According to the actual strain parameters of the bearing end surfaces (130, 140) and the pre-established corresponding relationship between the strain parameters of the bearing end surfaces (130, 140) and the strain parameters of the bolt holes (1-54), the said The strain parameter of the bolt hole (1~54). 3. The monitoring method according to claim 1, wherein the monitoring method specifically comprises: The corresponding relationship between the strain parameters of the bearing end faces (130, 140) and the strain parameters of the bolt holes (1-54) is established in advance, Monitoring temperature parameters and strain parameters of the bolt holes (1-54) by using the fiber Bragg grating sensing measurement system (500); correcting the strain parameters of the bolt holes (1-54) by using the temperature parameters of the bolt holes (1-54), so as to obtain the actual strain parameters of the bolt holes (1-54); According to the actual strain parameters of the bolt holes (1-54) and the pre-established correspondence between the strain parameters of the bearing end surfaces (130, 140) and the strain parameters of the bolt holes (1-54), the said Strain parameters of the bearing end faces (130, 140). 4. A monitoring system (800) for a pitch bearing (100), the pitch bearing (100) comprising a bearing end face (130, 140) and bolt holes opened on the bearing end face (130, 140) (1-54), characterized in that the monitoring system (800) includes: An optical fiber grating sensing and measuring system (500), which monitors temperature parameters and strain parameters of the bearing end faces (130, 140) or the bolt holes (1-54); and The correction unit (500a) uses the temperature parameters to correct the strain parameters of the bearing end surfaces (130, 140) or the bolt holes (1-54), so as to obtain actual strain parameters. 5. The monitoring system (800) according to claim 4, characterized in that, The fiber grating sensing and measuring system (500) monitors temperature parameters and strain parameters of the bearing end faces (130, 140), The correction unit (500a) corrects the strain parameter of the bearing end surface (130, 140) by using the temperature parameter of the bearing end surface (130, 140), so as to obtain the actual strain of the bearing end surface (130, 140) parameter, The monitoring system (800) further includes an acquisition unit (600), and the acquisition unit (600) pre-establishes the relationship between the strain parameters of the bearing end faces (130, 140) and the strain parameters of the bolt holes (1-54). Corresponding relationship, and according to the actual strain parameters of the bearing end surface (130, 140) and the pre-established corresponding relationship between the strain parameters of the bearing end surface (130, 140) and the strain parameters of the bolt holes (1-54) to obtain the strain parameters of the bolt holes (1-54). 6. The monitoring system (800) according to claim 4, characterized in that, The fiber grating sensing measurement system (500) monitors the temperature parameters and strain parameters of the bolt holes (1-54), The correction unit (500a) uses the temperature parameters of the bolt holes (1-54) to correct the strain parameters of the bolt holes (1-54), so as to obtain the actual strain of the bolt holes (1-54) parameter, The monitoring system (800) further includes an acquisition unit (600), and the acquisition unit (600) pre-establishes the relationship between the strain parameters of the bearing end faces (130, 140) and the strain parameters of the bolt holes (1-54). Corresponding relationship, and according to the actual strain parameters of the bolt holes (1-54) and the pre-established corresponding relationship between the strain parameters of the bearing end surface (130, 140) and the strain parameters of the bolt holes (1-54) to obtain the strain parameter of the bearing end surface (130, 140). 7. The monitoring system (800) according to claim 5 or 6, characterized in that, the fiber grating sensing measurement system (500) includes a pair of the bearing end face (130, 140) and the bolt hole (1 ～54) the fiber grating sensor (200) that collects the optical signal of temperature parameter and strain parameter, and described fiber grating sensor (200) is respectively arranged at 0 °, 90 °, 180 ° and 270 ° of the circumference of described bearing end face place. 8. The monitoring system (800) according to claim 7, characterized in that, the fiber grating sensor (200) is also arranged at 0°, 90°, 180° and 270° of the pitch bearing (100) in the said bolt holes (1,14,28,41). 9. The monitoring system (800) according to claim 7, characterized in that, multiple fiber grating sensors (200) are arranged at 0° and 180° of the circumference of the bearing end face. 10. The monitoring system (800) according to claim 8, characterized in that, the fiber grating sensor (200) is axially or radially mounted on the inner wall of the bolt hole (1, 14, 28, 41) Install. 11. according to the monitoring system (800) described in any one in claim 4 to 10, it is characterized in that, described optical fiber grating sensing measurement system (500) also comprises to collect by described optical fiber grating sensor (200) An optical demodulator (400) for analyzing the optical signal, the fiber grating sensor (200) is connected with the optical demodulator (400) through an optical fiber link (300), and the optical fiber link (300) The two ends are respectively connected with the optical demodulator (400).