Control method of water pump with bearing connection device

Abstract

The present invention relates to the field of pumping control technology, and in particular to a control method for a water pump with a bearing connection device, comprising pre-tightening the bearings in the water pump according to an initial pre-tightening force to determine the operating state of the water pump; determining whether the bearing clearance is in a light pre-tightening range in combination with the starting torque, adjusting the initial pre-tightening force or increasing the water pump load for secondary analysis; collecting the original vibration signal in the water pump, generating a vibration spectrum of the original vibration signal, and extracting the amplitude corresponding to the characteristic frequency in the vibration spectrum; judging whether the bearing has abnormal vibration according to the speed frequency amplitude, determining whether the cause type of the operating state of the water pump is an explicit cause or an implicit cause, and adopting a corresponding explicit processing strategy or implicit processing strategy; and performing a limit correction on the process of determining the operating state of the water pump according to the operating time of the water pump. The present invention manages the bearing pre-tightening force of the water pump and intelligently diagnoses and controls the operating state of the water pump.

Description

Technical Field

[0001] The present invention relates to the technical field of pumping control, and in particular to a control method for a water pump with a bearing connection device. Background Art

[0002] A water pump is a common fluid conveying equipment, widely used in agricultural irrigation, industrial production, building water supply, fire protection water supply and other fields, mainly used for lifting and conveying liquids; the structure of a common water pump is mainly composed of a pump body, impeller, shaft seal device, prime mover and bearings, etc. When in use, it is connected to the casing through bearings. Therefore, the bearing is one of the key components of the water pump, and its performance and quality directly affect the operating efficiency and life of the water pump; whether the water pump rolling bearing is installed correctly affects the accuracy, life and performance of the water pump. It can be seen that the installation and operation of the water pump rolling bearing must be fully controlled and studied.

[0003] Chinese Patent Publication No.: CN118361410A discloses a method and device for controlling the water flow of a magnetic levitation centrifugal unit; wherein, the method includes, after determining that the motor of the magnetic levitation centrifugal unit is started, obtaining the motor operating frequency of the motor; when it is determined that the motor operating frequency reaches the starting frequency of the motor, obtaining the bearing displacement of the shaft in the magnetic levitation centrifugal unit, wherein the bearing displacement is the offset between the real-time position of the shaft and the reference position; comparing the displacement signal corresponding to the bearing displacement with the reference displacement signal to obtain a comparison result; determining a control strategy for a water pump in the magnetic levitation centrifugal unit based on the comparison result; controlling the water pump to control the water flow according to the control strategy so that the water flow is greater than a water flow threshold; the invention solves the technical problem in the related art that the cooling water flow of the water pump of the magnetic levitation centrifugal unit is too low and the condensing pressure is too high, resulting in poor bearing accuracy.

[0004] In the prior art, since the water pump drive shaft drives the bearing to rotate at high speed, and the bearing accuracy is affected by the preload degree, the bearing is prone to operating problems such as wear and vibration. Summary of the Invention

[0005] To this end, the present invention provides a control method for a water pump with a bearing connection device, which is used to overcome the problem in the prior art that the bearing is prone to wear and vibration due to the water pump drive shaft driving the bearing to rotate at high speed and the bearing accuracy being affected by the preload degree.

[0006] To achieve the above object, the present invention provides a control method for a water pump having a bearing connection device, comprising:

[0007] Preload the bearings in the water pump according to the initial preload force, obtain the starting torque of the water pump under no-load conditions, and determine the operating state of the water pump based on the actual power corresponding to the water pressure of the water pump body;

[0008] determining whether the bearing clearance is within a slight preload range based on the operating state and the starting torque, and adjusting the initial preload force or increasing the water pump load for secondary analysis based on the determination result;

[0009] After adjusting the initial preload or when performing secondary analysis, collecting the original vibration signal in the water pump, generating a vibration spectrum of the original vibration signal, and extracting the amplitude corresponding to the characteristic frequency in the vibration spectrum;

[0010] Determine whether the bearing has abnormal vibration based on the speed frequency amplitude, determine whether the cause of the pump's operating status is an explicit cause or a hidden cause, and adopt corresponding explicit or hidden treatment strategies;

[0011] The explicit processing strategy is to determine the cause and extent of abnormal vibration according to the outer ring passing frequency amplitude when the bearing has abnormal vibration, and increase the initial preload according to the initial amplitude or control the water pump to stop;

[0012] The implicit processing strategy is to determine the water pump control mode according to the comprehensive status index of the bearing, and adjust the valve opening of the water pump inlet pipe and the water outlet pipe and the water pump flow rate;

[0013] A limit correction is performed on a process for determining the operating state of the water pump according to the operating time of the water pump.

[0014] Furthermore, the process of determining the operating state of the water pump includes:

[0015] Real-time detection of the water pressure of the water pump body. When the water pressure of the water pump body reaches the standard water pressure, the actual power of the water pump motor is detected, and the power difference between the actual power and the theoretical power corresponding to the standard water pressure is calculated;

[0016] If the power difference is less than or equal to the difference evaluation value, it is determined that the water pump is in the first operating state; if the power difference is greater than the difference evaluation value, it is determined that the water pump is in the second operating state.

[0017] Furthermore, the process of determining whether the bearing clearance is in the slight preload range includes:

[0018] Establish a conversion relationship between the starting torque of the water pump motor and the preload force corresponding to the preload amount, and compare the starting torque with the standard torque.

[0019] If the starting torque is less than the first standard torque, it is judged that the bearing clearance in the water pump is too large and there is positive clearance in the preload amount, so the initial preload force on the bearing is increased;

[0020] If the starting torque is greater than or equal to the first standard torque and less than the second standard torque, it is determined that the bearing clearance in the water pump is in the slight preload range, and the standard water pressure is increased for secondary analysis;

[0021] If the starting torque is greater than or equal to the second standard torque, it is determined that the clearance of the bearing in the water pump is too small and over-preloaded, and the initial preload force on the bearing is reduced.

[0022] Furthermore, when the clearance is in the slight preload range or after the preload force is adjusted, the peak value of the speed frequency point in the vibration spectrum is extracted as the speed frequency amplitude;

[0023] If the speed frequency amplitude is less than the speed frequency standard value, it is judged that there is no abnormal vibration of the water pump; if the speed frequency amplitude is greater than or equal to the speed frequency standard value, it is judged that the speed frequency amplitude exceeds the standard and the water pump has abnormal vibration.

[0024] Furthermore, the water pump has abnormal vibration, and the cause type of the water pump being in the second operating state is determined to be an explicit cause, and an explicit processing strategy is adopted;

[0025] There is no abnormal vibration in the water pump. The reason why the water pump is in the second operating state is determined to be a hidden cause, and a hidden processing strategy is adopted.

[0026] Furthermore, the process of determining the cause and extent of abnormal vibration includes:

[0027] Calculate the outer ring passing frequency of the bearing and extract the outer ring passing frequency amplitude corresponding to the outer ring passing frequency point.

[0028] If the speed frequency amplitude exceeds the standard, but the outer ring pass frequency amplitude does not exceed the standard, it is judged that the bearing preload is insufficient, resulting in abnormal vibration. Increase the initial preload force according to the initial amplitude;

[0029] If the speed frequency amplitude exceeds the standard and the outer ring pass frequency amplitude exceeds the standard, it is judged that the abnormal vibration has caused bearing wear, and the water pump is controlled to stop and a maintenance alarm is triggered.

[0030] Furthermore, the condition for determining whether the outer ring pass frequency amplitude exceeds the standard is that the outer ring pass frequency amplitude is greater than the pass frequency standard value.

[0031] Furthermore, the bearing status is monitored in real time according to the initial detection period, and the comprehensive status index of the bearing is determined based on the detected bearing temperature and real-time axial force.

[0032] Furthermore, the comprehensive status index is compared with a preset index range.

[0033] If the comprehensive status indicator is within the preset indicator range, high-frequency monitoring is started to reduce the initial detection cycle and water pump flow, increase the initial preload force and the oil supply of the auxiliary lubrication pump in the water pump;

[0034] If the comprehensive status index is lower than the preset index range, the bearing status is judged to be abnormal, the load is reduced, and an early warning signal is issued for operation and maintenance;

[0035] If the comprehensive status index is higher than the preset index range, it is determined that the current preload force is maintained, and the initial detection period is increased according to the ratio of the comprehensive status index to the median of the preset index.

[0036] Furthermore, the difference evaluation value is reduced according to the operating time of the water pump.

[0037] Compared with the prior art, the beneficial effect of the present invention is that due to the different models, sizes and specific structures of water pumps, the installation and setting methods of the bearings required by the water pumps in the water pumps are also different, and the bearings are key components in the water pump transmission system, responsible for supporting the rotor, transmitting power and reducing friction. Their design directly affects the operating efficiency, life and reliability of the water pump. The present method verifies whether the operating condition of the water pump is good based on the actual power when the water pump is running with load and the starting torque when the water pump is no-load, thereby increasing the flexibility and adaptability of determining the operating condition of the water pump; and since the bearing clearance refers to the gap between the rolling element and the inner and outer rings inside the bearing, it directly affects The selection of water pump bearing clearance is particularly critical because it affects the bearing's load capacity, operating temperature, vibration and life. Therefore, this method reflects the preload condition through the starting torque of the water pump after eliminating the influence of the water pump load, that is, whether the clearance existing in the water pump bearing after preload is in an appropriate range. When it is not in an appropriate range, the preload force is adjusted to control the bearing clearance. The rolling element and the raceway are properly contacted by applying axial force to eliminate the working clearance. The relative position of the bearing in the water pump is adjusted to meet the water pump operation requirements. By adjusting the relative position of the bearing in the water pump, the bearing clearance in the water pump is optimized, the operating condition of the water pump is improved, the working efficiency of the water pump is improved, and energy is saved.

[0038] Furthermore, the selection of the clearance of the water pump bearing is particularly critical, and the load, speed, temperature and installation conditions must be comprehensively considered. Among them, the change in vibration is the first to be measured, and the time from the generation of vibration to the actual failure is the longest. There is still enough time to intervene to ensure that the failure does not occur; therefore, this method extracts the speed frequency amplitude value from the original vibration signal generated in the water pump, determines whether the water pump has abnormal vibration, and thus determines the type of reason why the water pump is in the second operating state, and adopts corresponding processing strategies accordingly, thereby increasing the diagnosis and determination of adverse factors affecting the operation of the water pump, thereby controlling the efficiency of the water pump to adopt corresponding measures, and directly reflects the mass imbalance or poor alignment of the rotor system in the water pump; at the same time, when the water pump has abnormal vibration, the cause of the vibration and whether the vibration intensity is large enough to cause the bearing to be damaged are determined according to the frequency amplitude value of the outer ring, thereby increasing the accuracy and adaptability of control and adjustment for different working conditions of the water pump.

[0039] Furthermore, this method reflects the preload state by directly measuring the axial load borne by the bearing, judges the friction power consumption and thermal deformation by temperature rise, prevents the cage from breaking, and reduces the friction power consumption by precise preload. According to the comprehensive state index, a hierarchical control strategy is adopted to implement measures, and the current parameters are maintained at the optimal state to optimize energy efficiency. Active intervention is made in the preset index range to make step adjustments to the preload and reduce the load accordingly to assist lubrication to avoid a sharp increase in temperature. In the event of serious abnormalities, protective operation is carried out to reduce the load and issue an early warning signal; through multi-parameter fusion calculation, single parameter misjudgment is avoided, and a hierarchical strategy from fine-tuning to emergency shutdown is adopted to take into account efficiency and safety, extend the equipment life cycle and improve the safety rating; at the same time, the operating characteristics of the water pump include the high dynamics of the axial force it is subjected to and the slow time-varying temperature generated. This method increases the flexibility and accuracy of controlling the water pump by setting weights of different sizes for temperature data and axial force data.

[0040] Furthermore, when the water pump is controlled and adjusted, the water pump is prone to problems such as a decline in operating status due to the accumulated operating time. Different operating times of the water pump affect the judgment of the operating status of the water pump. This method compensates for the life attenuation of the water pump operating status judgment standard according to the operating time of the water pump, and corrects the limit of the water pump control method, thereby increasing the adaptability and accuracy of the analysis, control and adjustment of the water pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is an overall flow chart of a method for controlling a water pump with a bearing connection device according to an embodiment of the present invention;

[0042] Figure 2 This is a flow chart for determining the operating status of a water pump in an embodiment of the present invention;

[0043] Figure 3 Schematic diagram of the clearance, preload force, and axial and radial structure of an angular contact ball bearing in an embodiment of the present invention;

[0044] Figure 4 Schematic diagram of the structure of an angular contact ball bearing and bearings in different preload ranges in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0046] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0047] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0048] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0049] See also Figure 1 - Figure 4 As shown, Figure 1 This is an overall flow chart of a method for controlling a water pump with a bearing connection device according to an embodiment of the present invention; Figure 2 This is a flow chart for determining the operating status of a water pump in an embodiment of the present invention; Figure 3 Schematic diagram of the clearance, preload force, and axial and radial structure of an angular contact ball bearing in an embodiment of the present invention; Figure 4 Schematic diagram of the structure of an angular contact ball bearing and bearings in different preload ranges in an embodiment of the present invention.

[0050] Figure 2 Rx is the axial clearance, Ry is the radial clearance, F is the preload force, Dx is the axial direction, and Dy is the radial direction.

[0051] The present invention provides a control method for a water pump having a bearing connection device, comprising:

[0052] Step S1: pre-tighten the bearings in the water pump according to the initial pre-tightening force, obtain the starting torque of the water pump under no-load conditions, and determine the operating state of the water pump based on the actual power corresponding to the water pressure of the water pump body;

[0053] Step S2, determining the preload range of the bearing clearance according to the operating state and the starting torque, and adjusting the initial preload force or increasing the water pump load for secondary analysis according to the determination result;

[0054] Step S3, after adjusting the initial preload or performing secondary analysis, collecting the original vibration signal in the water pump, generating a vibration spectrum of the original vibration signal, and extracting the amplitude corresponding to the characteristic frequency in the vibration spectrum;

[0055] Step S4: judging whether the bearing has abnormal vibration according to the speed frequency amplitude, determining whether the cause of the water pump's operating state is an explicit cause or a hidden cause, and adopting a corresponding explicit treatment strategy or a hidden treatment strategy;

[0056] Step S5, the explicit processing strategy is to determine the cause and extent of abnormal vibration according to the outer ring pass frequency amplitude when the bearing has abnormal vibration, and increase the initial preload according to the initial amplitude or control the water pump to stop;

[0057] Step S6, the implicit processing strategy is to determine the water pump control mode according to the comprehensive state index of the bearing, and adjust the valve opening of the water inlet pipe and the water outlet pipe of the water pump and the water pump flow rate;

[0058] Step S7, performing limit correction on the process of determining the operating state of the water pump according to the operating time of the water pump;

[0059] The judgment condition for the explicit cause and the implicit cause is whether there is abnormal vibration in the current operating state of the bearing.

[0060] In this embodiment, the water pump is a non-variable displacement pump, and the bearing of the water pump is an angular contact ball bearing. The angular contact ball bearing is a specially designed rolling bearing with an increased internal contact angle design that can withstand radial loads and axial loads. The contact angle and internal and external structures can be optimized to improve accuracy and speed capabilities to meet the high-speed operation requirements of the water pump motor.

[0061] Set the water pump to no load, preload the bearings in the water pump according to the initial preload force, start the water pump motor, and measure the starting torque of the motor at low speed under no-load conditions;

[0062] Open the water inlet pipe valve of the water pump and close the water outlet pipe valve to fill the water. The water pressure of the water pump body is detected in real time through the pressure sensor in the pump body.

[0063] When the water pressure in the pump body reaches the standard water pressure, the actual speed of the pump shaft and the actual power of the pump motor are detected, and the power difference between the actual speed and the theoretical power corresponding to the standard water pressure is calculated.

[0064] If the power difference is less than or equal to the difference evaluation value, it is determined that the water pump is in the first operating state;

[0065] If the power difference is greater than the difference evaluation value, it is determined that the water pump is in the second operating state;

[0066] Among them, the difference evaluation value is 2% of the theoretical power, the standard water pressure can be set by yourself, and the theoretical power is a preset value set according to the historical data of the motor power when the water pump reaches the standard water pressure.

[0067] During implementation, for self-priming pumps, the pump body must be filled in advance; for non-self-priming pumps, ensure that the suction port is immersed in the liquid; the initial preload force = K × (n / 1000)² × D, K = 0.7 is the operating coefficient of the clean water pump, n is the pump shaft speed of the water pump, and D is the bearing pitch circle diameter.

[0068] When the water pump is in the second operating state, obtaining the measured starting torque of the water pump motor under no-load condition;

[0069] Specifically, after using a torque meter to measure the starting torque of the motor at no-load startup, the Torque-Set method can be used to roughly estimate the bearing preload based on the starting torque. The principle of the Torque-Set method is to establish a conversion relationship between the starting torque and preload of the bearing through experimental testing. The preload can be estimated from the measured starting torque.

[0070] Therefore, in this embodiment, the setting of the preload force can be inferred by measuring the starting torque, and the preload force on the angular contact ball bearing determines the clearance existing in the bearing;

[0071] Establish a conversion relationship between the starting torque of the water pump motor and the preload corresponding to the preload amount, and compare the starting torque with the standard torque.

[0072] If the starting torque is less than the first standard torque, it is judged that the bearing clearance in the water pump is too large and there is positive clearance in the preload amount, so the initial preload force on the bearing is increased;

[0073] Specifically, the initial preload applied to the bearing is increased according to the ratio of the average standard torque to the starting torque;

[0074] If the starting torque is greater than or equal to the first standard torque and less than the second standard torque, it is determined that the bearing clearance in the water pump is in the slight preload range, and the standard water pressure is gradually increased for further analysis;

[0075] If the starting torque is greater than or equal to the second standard torque, it is determined that the bearing clearance in the water pump is too small and over-preloaded, and the initial preload force on the bearing is reduced;

[0076] Specifically, the initial preload force on the bearing is reduced according to the ratio of the starting torque to the average value of the standard torque;

[0077] The first standard torque is smaller than the second standard torque, and the average standard torque is the average of the first standard torque and the second standard torque.

[0078] The first standard torque and the second standard torque are preset values ​​set according to historical data of starting torque corresponding to the preload force when the bearings in the water pump are preloaded and there are positive and negative clearances of different sizes.

[0079] Specifically, due to the different models, sizes and specific structures of water pumps, the installation and setting methods of the bearings required by the water pumps in the water pumps are also different. The bearings are key components in the water pump transmission system, responsible for supporting the rotor, transmitting power and reducing friction. Their design directly affects the operating efficiency, life and reliability of the water pump. This method verifies whether the operating condition of the water pump is good based on the actual power when the water pump is running under load and the starting torque when the water pump is no-load, which increases the flexibility and adaptability of determining the operating status of the water pump. In addition, since the bearing clearance refers to the gap between the rolling elements and the inner and outer rings inside the bearing, it directly affects the bearing's load-bearing capacity. Force, operating temperature, vibration and life, the selection of the clearance of the water pump bearing is particularly critical. Therefore, this method reflects the preload condition by the starting torque of the water pump excluding the influence of the water pump load, that is, whether the clearance of the bearing in the water pump after preload is in an appropriate range. When it is not in the appropriate range, the preload force is adjusted to control the clearance of the bearing. By applying axial force, the rolling element and the raceway are properly contacted to eliminate the working clearance, and the relative position of the bearing in the water pump is adjusted to meet the operation requirements of the water pump. By adjusting the relative position of the bearing in the water pump, the clearance of the bearing in the water pump is optimized, the operating condition of the water pump is improved, the working efficiency of the water pump is improved, and energy is saved.

[0080] When the clearance is in the slight preload range or after the preload force is adjusted, determine the type of reason why the pump is in the second operating state and determine the corresponding treatment strategy;

[0081] A high-frequency accelerometer installed in the radial direction of the bearing seat is used to collect the original vibration signal generated by the bearing in the water pump, generate a vibration spectrum of the original vibration signal, and extract the amplitude corresponding to the characteristic frequency in the vibration spectrum;

[0082] Specifically, in this embodiment, the characteristic frequencies include the rotational speed frequency and the outer ring passing frequency, and the amplitude corresponding to the characteristic frequencies refers to the peak values ​​of the rotational speed frequency and the outer ring passing frequency at corresponding frequency points in the vibration spectrum;

[0083] If the speed frequency amplitude is greater than or equal to the speed frequency standard value, it is determined that the speed frequency amplitude exceeds the standard, the bearing is in abnormal vibration in the current operating state, and the reason type for the water pump to be in the second operating state is an explicit reason. The explicit processing strategy is adopted;

[0084] The peak value of the speed frequency point in the vibration spectrum is extracted as the speed frequency amplitude. If the speed frequency amplitude is less than the speed frequency standard value, it is determined that there is no abnormal vibration in the current operating state of the bearing. The reason type for the water pump being in the second operating state is hidden, and the hidden processing strategy is adopted;

[0085] The standard value of the rotation frequency is 2.5 mm / s.

[0086] The explicit processing strategy is to determine the cause and extent of abnormal vibration based on the outer ring passing frequency amplitude when abnormal vibration occurs in the current operating state of the bearing;

[0087] Calculate the outer ring passing frequency of the bearing, which is 0.4 × n × (D / d + 1), where n is the pump shaft speed, D is the bearing pitch diameter, and d is the rolling element diameter;

[0088] Specifically, when there are defects such as peeling and cracks on the outer ring of the bearing, the rolling element will generate an impact vibration each time it passes through the defect point. The outer ring passing frequency refers to the characteristic frequency generated when the rolling element (ball or roller) in the rolling bearing periodically passes through a fixed defect point on the outer ring.

[0089] Extract the vibration intensity corresponding to the frequency point where the outer ring passes through by FFT spectrum analysis as the outer ring passing frequency amplitude value, which is the peak amplitude corresponding to the frequency point where the outer ring passes through in the vibration spectrum;

[0090] If the speed frequency amplitude exceeds the standard, but the outer ring pass frequency amplitude does not exceed the standard and is within the normal range, it is determined that the bearing preload is insufficient, resulting in abnormal vibration. The explicit strategy is to increase the initial preload according to the initial amplitude;

[0091] Specifically, the initial amplitude is 15%;

[0092] If the speed frequency amplitude exceeds the standard and the outer ring pass frequency amplitude exceeds the standard, it is determined that abnormal vibration has caused bearing wear. The explicit strategy handles this by controlling the water pump to stop and triggering a maintenance alarm.

[0093] Specifically, the condition for determining whether the outer ring pass frequency amplitude exceeds the standard is that the outer ring pass frequency amplitude is greater than the pass frequency standard value;

[0094] The standard value of the frequency band is 0.5g, which is 4.9m / s. 2 .

[0095] Specifically, the selection of the clearance of the water pump bearing is particularly critical, and the load, speed, temperature and installation conditions must be comprehensively considered. Among them, the change in vibration is the first to be measured, and the time from the generation of vibration to the actual failure is the longest. There is still enough time to intervene to ensure that the failure does not occur; therefore, this method extracts the speed frequency amplitude value of the original vibration signal generated in the water pump, determines whether the water pump has abnormal vibration, and thus determines the type of reason why the water pump is in the second operating state, and adopts corresponding processing strategies accordingly, which increases the diagnosis and determination of adverse factors affecting the operation of the water pump, thereby controlling the efficiency of the water pump to adopt corresponding measures, and directly reflects the mass imbalance or poor alignment of the rotor system in the water pump; at the same time, when the water pump has abnormal vibration, the cause of the vibration and whether the vibration intensity is large enough to cause the bearing to be damaged are determined according to the frequency amplitude value of the outer ring, which increases the accuracy and adaptability of control and adjustment for different working conditions of the water pump.

[0096] Specifically, the implicit processing strategy is to determine the water pump control mode according to the comprehensive status index of the bearing;

[0097] The bearing status is monitored in real time by the axial force sensor and the temperature sensor according to the initial detection period. The bearing temperature is detected and the bearing temperature rise ΔT during the initial detection period is calculated. The real-time axial force is detected and the deviation Fe between the real-time axial force and the target value is calculated to determine the comprehensive bearing status index H.

[0098] The comprehensive status index H=W1(1-Fe / Fm)+W2(1-ΔT / Tm), where W1 is the axial force data weight, W2 is the temperature data weight, Fe is the deviation between the real-time axial force and the target value, Fm is the maximum allowable axial force deviation, ΔT is the bearing temperature rise, and Tm is the maximum allowable temperature rise;

[0099] In this embodiment, Fm is 10% of the rated preload, Tm is 65°C, W1=0.7, and W2=0.3.

[0100] If the comprehensive status indicator H is within the preset indicator range, high-frequency monitoring is started to reduce the initial detection cycle and water pump flow, increase the initial preload force and the oil supply of the auxiliary lubrication pump in the water pump;

[0101] Specifically, the initial detection period is reduced based on the ratio of the minimum value of the preset indicator interval to the comprehensive status indicator, the initial preload force and oil supply volume are increased by 5%, and the valve openings of the water pump's water inlet and outlet pipes are adjusted to reduce the water pump's flow rate by 15%;

[0102] If the comprehensive status index H is lower than the preset index range, the bearing status is judged to be abnormal, the load is reduced, and an early warning signal is issued for operation and maintenance;

[0103] Specifically, the valve openings of the water pump's inlet and outlet pipes are adjusted to reduce the pump's flow rate by 30%;

[0104] If the comprehensive status index H is higher than the preset index range, it is determined to maintain the current preload force, and the initial detection period is increased according to the ratio of the comprehensive status index to the median of the preset index;

[0105] Among them, the preset indicator interval is (0.5, 0.7), and the preset indicator median is 0.6.

[0106] Specifically, this method reflects the preload state by directly measuring the axial load borne by the bearing, judges the friction power consumption and thermal deformation by temperature rise, prevents the cage from breaking, and reduces the friction power consumption by precise preload. According to the comprehensive status indicators, a hierarchical control strategy is adopted to implement measures, and the current parameters are maintained at the optimal state to optimize energy efficiency. Active intervention is made in the preset indicator range to make step adjustments to the preload and reduce the load accordingly to assist lubrication to avoid a sharp increase in temperature. In the event of serious abnormalities, protective operation is carried out to reduce the load and issue an early warning signal; through multi-parameter fusion calculation, single parameter misjudgment is avoided, and a hierarchical strategy from fine-tuning to emergency shutdown is adopted to take into account efficiency and safety, extend the equipment life cycle and improve the safety rating; at the same time, the operating characteristics of the water pump include the high dynamics of the axial force it is subjected to and the slow time-varying temperature generated. This method increases the flexibility and accuracy of controlling the water pump by setting weights of different sizes for temperature data and axial force data.

[0107] Negative feedback regulation is used to determine the parameters of the water pump operating status, and limit correction is performed according to the operating time. Specifically, the difference evaluation value is adjusted according to the operating time h, and the adjusted difference evaluation value = 2% × (1-h / 1000).

[0108] Specifically, when controlling and adjusting the water pump, the water pump is prone to problems such as a decline in operating status due to the accumulated operating time. Different operating times of the water pump affect the judgment of the operating status of the water pump. This method compensates for the life attenuation of the water pump operating status judgment standard according to the operating time of the water pump, and corrects the limit of the water pump control method, thereby increasing the adaptability and accuracy of the analysis, control and adjustment of the water pump.

[0109] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A method for controlling a water pump having a bearing connection device, characterized in that: include: Preload the bearings in the water pump according to the initial preload force, obtain the starting torque of the water pump under no-load conditions, and determine the operating state of the water pump based on the actual power corresponding to the water pressure of the water pump body; determining whether the bearing clearance is within a slight preload range based on the operating state and the starting torque, and adjusting the initial preload force or increasing the water pump load for secondary analysis based on the determination result; After adjusting the initial preload or when performing secondary analysis, collecting the original vibration signal in the water pump, generating a vibration spectrum of the original vibration signal, and extracting the amplitude corresponding to the characteristic frequency in the vibration spectrum; Determine whether the bearing has abnormal vibration based on the speed frequency amplitude, determine whether the cause of the pump's operating status is an explicit cause or a hidden cause, and adopt corresponding explicit or hidden treatment strategies; The explicit processing strategy is to determine the cause and extent of abnormal vibration based on the outer ring passing frequency amplitude when the bearing has abnormal vibration, and increase the initial preload according to the initial amplitude or control the water pump to stop; The implicit processing strategy is to determine the water pump control mode according to the comprehensive status index of the bearing, and adjust the valve opening of the water pump inlet pipe and the water outlet pipe and the water pump flow rate; Performing limit correction on the process of determining the operating state of the water pump according to the operating time of the water pump; The process of determining the operating state of the pump includes: Real-time detection of the water pressure of the water pump body. When the water pressure of the water pump body reaches the standard water pressure, the actual power of the water pump motor is detected, and the power difference between the actual power and the theoretical power corresponding to the standard water pressure is calculated; If the power difference is less than or equal to the difference evaluation value, it is determined that the water pump is in the first operating state; If the power difference is greater than the difference evaluation value, it is determined that the water pump is in the second operating state; The process of determining whether the bearing clearance is in the light preload range includes, Establish a conversion relationship between the starting torque of the water pump motor and the preload force corresponding to the preload amount, and compare the starting torque with the standard torque; If the starting torque is less than the first standard torque, it is judged that the bearing clearance in the water pump is too large and there is positive clearance in the preload amount, so the initial preload force on the bearing is increased; If the starting torque is greater than or equal to the first standard torque and less than the second standard torque, it is determined that the bearing clearance in the water pump is in the slight preload range, and the standard water pressure is increased for secondary analysis; If the starting torque is greater than or equal to the second standard torque, it is determined that the clearance of the bearing in the water pump is too small and over-preloaded, and the initial preload force on the bearing is reduced.

2. The control method of a water pump equipped with a bearing connection device according to claim 1, characterized in that: When the clearance is in the slight preload range or after the preload force is adjusted, the peak value of the speed frequency point in the vibration spectrum is extracted as the speed frequency amplitude; If the speed frequency amplitude is less than the speed frequency standard value, it is judged that there is no abnormal vibration of the water pump; if the speed frequency amplitude is greater than or equal to the speed frequency standard value, it is judged that the speed frequency amplitude exceeds the standard and the water pump has abnormal vibration.

3. The control method of a water pump equipped with a bearing connection device according to claim 2, characterized in that: When the water pump has abnormal vibration, it is determined that the cause of the water pump being in the second operating state is an explicit cause, and an explicit processing strategy is adopted; When the water pump does not have abnormal vibration, it is determined that the cause type of the water pump being in the second operating state is a hidden cause, and a hidden processing strategy is adopted.

4. The control method of a water pump equipped with a bearing connection device according to claim 3, characterized in that: The process of determining the cause and extent of abnormal vibration includes: Calculate the outer ring passing frequency of the bearing and extract the outer ring passing frequency amplitude corresponding to the outer ring passing frequency point; If the speed frequency amplitude exceeds the standard, but the outer ring pass frequency amplitude does not exceed the standard, it is judged that the bearing preload is insufficient, resulting in abnormal vibration. Increase the initial preload force according to the initial amplitude; If the speed frequency amplitude exceeds the standard and the outer ring pass frequency amplitude exceeds the standard, it is judged that the abnormal vibration has caused bearing wear, and the water pump is controlled to stop and a maintenance alarm is triggered.

5. The control method of a water pump equipped with a bearing connection device according to claim 4, characterized in that: The condition for determining whether the outer ring pass frequency amplitude exceeds the standard is that the outer ring pass frequency amplitude is greater than the pass frequency standard value.

6. The method for controlling a water pump equipped with a bearing connection device according to claim 1, wherein: The bearing status is monitored in real time according to the initial detection cycle, and the comprehensive bearing status index is determined based on the detected bearing temperature and real-time axial force.

7. The control method of a water pump equipped with a bearing connection device according to claim 6, characterized in that: Compare the comprehensive status index with the preset index range, If the comprehensive status indicator is within the preset indicator range, high-frequency monitoring is started to reduce the initial detection cycle and water pump flow, increase the initial preload force and the oil supply of the auxiliary lubrication pump in the water pump; If the comprehensive status index is lower than the preset index range, the bearing status is judged to be abnormal, the load is reduced, and an early warning signal is issued for operation and maintenance; If the comprehensive status index is higher than the preset index range, it is determined that the current preload force is maintained, and the initial detection period is increased according to the ratio of the comprehensive status index to the median of the preset index.

8. The method for controlling a water pump equipped with a bearing connection device according to claim 1, wherein: The difference evaluation value is reduced according to the operating time of the water pump.

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