A turbine disk turning loading test device and loading control method

Abstract

A kind of steam turbine turning loading test device and loading control method, it is related to steam turbine test equipment technical field, wherein turning loading test device includes steam turbine turning assembly, loading execution unit and loading control unit, loading execution unit is set to two groups, and two groups of loading execution unit are respectively arranged at the both ends of worm shaft and synchronously opposite and apply axial loading force;Each group of loading execution unit includes ball screw stepper motor, bearing cover and spherical loading head;Ball screw stepper motor is fixed to the outside of bearing cover, and its screw rod passes through bearing cover and is fixedly connected with spherical loading head, and spherical loading head is abutted on the shaft end of worm shaft.Using the device and method can complete the simulation of load condition in factory, reproduce the real stress state of turning field operation, effectively complete the running-in of soft gear sleeve and worm, so as to avoid the fault of copper chip drop caused by poor meshing degree of worm gear, solve the problem that meshing defect cannot be detected and assembly size cannot be optimized in advance in empty load test.

Description

Technical Field

[0001] This invention relates to the field of steam turbine testing equipment technology, specifically to a steam turbine turning gear loading test device and loading control method. Background Technology

[0002] The turning gear is a core component of the steam turbine, primarily used during turbine start-up and shutdown. It drives the turbine and generator shafts to rotate continuously via a turning gear motor, preventing thermal bending deformation of the hot rotor during shutdown and ensuring safe start-up and shutdown. In actual operation, the turbine turning gear assembly, through drive gear meshing with coupling gears, drives the rotor to accelerate, decelerate, and rotate at a constant speed along a predetermined curve during turbine start-up and shutdown. The turning gear worm gear employs a copper soft-tooth sleeve structure; the meshing accuracy and running-in degree of its tooth surface with the steel worm directly determine the operational reliability and service life of the turning gear.

[0003] Currently, most manufacturers of turning gears only conduct no-load tests before shipment. Under these conditions, the copper soft sleeve of the worm gear and the tooth surface of the worm differ significantly from actual operation, making effective running-in impossible. Manual loading running-in methods suffer from low loading accuracy, large load fluctuations, and cumbersome and inefficient operation. When a turning gear is not fully run-in in the field, copper soft sleeves of the worm gear may shed copper shavings. These detached copper shavings can contaminate the lubricating oil, clog filters, cause oil pressure drops triggering shutdowns, and exacerbate Babbitt alloy wear in the bearings. In severe cases, this can lead to major accidents such as bearing burnout, turning gear failure, and rotor thermal bending.

[0004] Specifically, the existing technology has the following drawbacks: (1) The no-load test cannot simulate the actual load condition. The contact stress on the meshing surface of the worm gear is much smaller than the actual operating condition, and it cannot effectively expose the meshing defects caused by machining and assembly errors. (2) Manual loading relies on manual operation, resulting in low precision in load force control, large load fluctuations, poor repeatability of test data, and inability to guarantee the running-in quality. (3) There is a lack of effective online monitoring methods, making it impossible to grasp the meshing state of the worm gear in real time and making it difficult to detect meshing abnormalities in a timely manner; (4) The test process has a low degree of automation, requiring manual monitoring and adjustment throughout, resulting in low test efficiency and high labor intensity; (5) Lack of a sound safety protection mechanism. When abnormal meshing, overload, jamming or other faults occur, the machine cannot be stopped in time for protection, which can easily cause equipment damage. (6) It is impossible to simulate the changes in load under different operating conditions during the start-up and shutdown of the unit, and the test conditions are significantly different from the actual operating conditions; (7) The loading control strategy is simple and cannot dynamically adjust the loading parameters according to the real-time working conditions. The efficiency and quality of the test need to be improved.

[0005] Therefore, there is an urgent need for a turning gear loading test device and method that can simulate the load operation of a steam turbine rotor in a factory, achieve precise worm gear running-in, and have intelligent control and multiple safety protections, in order to solve the above-mentioned problems in the existing technology. Summary of the Invention

[0006] The purpose of this invention is to propose a turbine turning gear loading test device and loading control method, which can simulate the load condition of the turbine turning gear in the factory, reproduce the real stress state of the turning gear in the field, effectively complete the running-in of the soft gear sleeve and worm, thereby avoiding the failure of copper shavings due to poor meshing of the worm gear and worm, and solving the problems of not being able to detect meshing defects and not being able to optimize assembly dimensions in advance during no-load testing.

[0007] The technical solution adopted in this invention is: a turbine turning gear loading test device, including a turbine turning gear assembly, a loading execution unit and a loading control unit, wherein the turbine turning gear assembly includes a bearing, a worm gear, a worm gear shaft, a turning gear cover, a drive gear, a turning gear motor and a worm.

[0008] The loading execution unit is configured as two sets, and the two sets of loading execution units are respectively arranged at both ends of the worm gear shaft and apply axial loading force synchronously towards each other; Each loading execution unit includes a lead screw stepper motor, a bearing cover, and a spherical loading head. The lead screw stepper motor is fixed to the outside of the bearing cover, and its lead screw passes through the bearing cover and is fixedly connected to the spherical loading head to drive the spherical loading head to make axial displacement. The spherical loading head abuts against the shaft end of the worm gear shaft and forms frictional contact to apply axial loading force to the worm gear shaft to form a controlled frictional resistance torque, simulating the rotor load during the start-up and shutdown process of the steam turbine. The loading control unit is connected to the turning motor, the current acquisition module, the displacement acquisition module and the lead screw stepper motor respectively. The current acquisition module is used to acquire the working current of the turning motor, and the displacement acquisition module is used to acquire the displacement signal of the worm gear shaft in two mutually perpendicular directions. The loading control unit establishes a loading closed-loop control based on the operating current of the turning gear motor, and adjusts the loading process of the lead screw stepper motor in combination with the shaft center trajectory formed by the displacement signal to simulate the variable operating load during the start-up and shutdown process of the steam turbine. When the current or displacement is detected to exceed the set threshold, the loading execution unit is controlled to unload and stop the turning gear operation.

[0009] As a preferred embodiment, the spherical loading head adopts a spherical structure and is connected to the lead screw output end of the lead screw type stepper motor through a reverse thread. The connection part is provided with a saddle pin to prevent the spherical loading head from loosening or rotating relative to the lead screw. The lead screw operating end is provided with an external hexagonal operating part for manual unloading when the lead screw type stepper motor fails.

[0010] As a preferred embodiment, the bearing cover is provided with an oil inlet and an oil return port, and the flow area of ​​the oil return port is 1.1 to 1.3 times that of the flow area of ​​the oil inlet, so as to form a lubricating oil circulation and carry away friction debris.

[0011] As a preferred embodiment, a displacement acquisition module is installed on at least one bearing cover; each displacement acquisition module includes an X-direction displacement sensor and a Y-direction displacement sensor located on the same cross section of the worm gear shaft and perpendicular to each other.

[0012] As a preferred option, the end face of the worm gear shaft is provided with a concave spherical groove that matches the convex spherical surface of the spherical loading head, so as to increase the contact area between the two.

[0013] A loading control method based on the turbine turning gear loading test device includes the following steps: Establish the target resistance torque and the corresponding variable operating condition loading curve based on the turbine start-up and shutdown conditions; Two sets of loading execution units are controlled to synchronously apply axial loading force to the worm gear shaft to form a controlled frictional resistance torque that simulates the turbine rotor load; The operating current of the rotating gear motor is collected in real time, and the feed speed and loading position of the loading execution unit are controlled according to the operating current to establish a loading closed-loop control. The displacement signals of the worm wheel shaft in two mutually perpendicular directions are acquired in real time and the shaft center trajectory is generated. The meshing state of the worm wheel and the worm is determined based on the shaft center trajectory. The loading rate is dynamically adjusted according to the rate of change of the operating current of the turning gear motor and the change of the shaft trajectory, so that the loading process runs according to the variable working condition loading curve. When the operating current, the fluctuation range of the operating current, or the displacement signal exceeds the preset threshold, the control loading execution unit will unload synchronously and stop the turning gear operation.

[0014] As a preferred embodiment, the target resistance torque includes the starting torque generated by overcoming the bearing friction resistance and the acceleration torque generated by the turning gear speed increase, and the target resistance torque corresponding to the speed increase loading stage, the uniform speed loading stage and the deceleration loading stage are established based on the two.

[0015] As a preferred embodiment, the loading closed-loop control includes: increasing the output of the loading execution unit when the operating current of the turning motor is lower than the target current; reducing the loading rate when the difference between the operating current and the target current is less than a preset difference; and maintaining the loading position to maintain constant loading when the operating current reaches the target current.

[0016] As a preferred embodiment, the dynamic adjustment of the loading rate includes: reducing the loading rate or pausing loading when the rate of change of the operating current of the turning gear motor exceeds a set threshold or when there is an abnormal change in the shaft center trajectory; and continuing loading when the rate of change of the operating current and the shaft center trajectory return to stability.

[0017] As a preferred option, after completing the loading test, the assembly dimensions of the worm gear and worm are adjusted according to the shaft trajectory, the contact state of the worm gear teeth, and the results of the wear debris detection. The loading test is repeated until the meshing state meets the preset requirements.

[0018] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention can realize the simulation of the load condition of the turbine turning gear before leaving the factory, replacing the traditional no-load test, accurately reproduce the real operating state of the turbine rotor under load, effectively run-in the copper outer tooth sleeve and worm of the worm gear, and truly expose the problem of poor meshing of the worm gear and worm caused by the cumulative error of processing and assembly. The assembly size of the worm gear and worm can be adjusted in time according to the test results, and the problem of copper shavings falling off the worm gear and worm can be avoided from the source when the equipment is running on site, thus ensuring the safe operation of the unit on site.

[0019] (2) The present invention uses a lead screw stepper motor as the core of loading execution, and works with the loading control unit to achieve closed-loop control, which can realize precise adjustment and stable maintenance of the loading load. The loading force control accuracy reaches ±1%FS, replacing the traditional manual adjustment structure and eliminating human operation error. The loading components set at opposite ends of the worm gear shaft are synchronously controlled by the control cabinet, which can ensure uniform force on the shaft system, avoid uneven loading and jamming, and greatly improve the stability of the test process and the accuracy of the test data.

[0020] (3) The present invention innovatively designs a spherical loading head structure, which is fixed by reverse thread connection and saddle pin. The surface wear resistance is enhanced by nitriding / carburizing process, and the surface hardness reaches HV800-1200. The spherical surface design can adaptively compensate for installation errors and insufficient end face flatness, always maintain a good contact state, ensure effective loading, and uniformly distribute contact stress to avoid stress concentration. An external hexagonal operating part is added to the screw operating end, which can be manually withdrawn when the motor is stuck, improving the maintainability and emergency handling capability of the device.

[0021] (4) The present invention adds displacement sensors in the X and Y directions of the bearing cover. The non-contact eddy current displacement sensor is used, with a measurement range of ±2mm and an accuracy of ±0.001mm. It can output the shaft center trajectory in real time, monitor the meshing of the worm gear and worm online, and detect meshing abnormalities in time. By setting displacement protection settings and over-limit shutdown logic, it can effectively prevent equipment damage caused by meshing abnormalities, and further improve the safety and automation level of the test process.

[0022] (5) The present invention innovatively designs a variable operating condition loading setting function, which can simulate the actual situation of load changes during the start-up and shutdown of the unit, and automatically adjust the loading force according to the preset variable operating condition loading curve, so that the test conditions are closer to the actual operating state and improve the authenticity and effectiveness of the test.

[0023] (6) The present invention innovatively designs an adaptive loading control algorithm, which judges the meshing state based on the change rate of the turning motor current and the displacement sensor signal, dynamically adjusts the loading rate, realizes intelligent loading control, shortens the test time and improves the test efficiency while ensuring the running-in quality; when the change rate of current exceeds the set threshold or the displacement signal shows meshing abnormality, the loading rate is automatically reduced or loading is paused, and the system continues after stabilization to avoid damage to the equipment.

[0024] (7) The present invention has a complete safety protection mechanism, including multiple protection measures such as overload protection, current fluctuation protection, displacement over-limit protection, and emergency stop protection. When an abnormality occurs, the load control unit immediately triggers the protection program, controls the lead screw stepper motor to quickly retract and unload, stops the turning motor, and records the abnormal data, thus ensuring the safety of equipment and personnel in all aspects.

[0025] (8) The present invention has a simple structure and strong adaptability. It can be quickly assembled with different models of turbine turning gear devices. The operation process is standardized and controllable. The locking and sealing structure is stable and reliable. It has both practicality and versatility and can be widely used in the factory loading test of various turbine turning gear devices. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the operating principle of the turbine turning gear assembly of the present invention; Figure 2 This is a schematic diagram of the overall assembly structure of the present invention; Figure 3 This is a schematic diagram of the main structure of the loading test device in this invention; Figure 4 This is a schematic diagram of the spherical loading head in this invention; Figure 5 This is a schematic diagram of the variable loading curve of the present invention; Figure 6 This is the normal power-on logic diagram of the present invention; Figure 7 This is the normal shutdown logic diagram of the present invention; Figure 8 This is the fault shutdown logic diagram of the present invention; Figure 9 This is the emergency stop control logic diagram of the present invention; Figure 10This is the adaptive loading control logic diagram of the present invention; Figure 11 This is the variable operating condition loading control logic diagram of the present invention.

[0028] Reference numerals: 1. Turning gear loading test device; 2. Bearing; 3. Worm gear; 4. Worm gear shaft; 5. Turning gear cover; 6. Drive gear; 7. Loading control unit; 8. Turning gear motor; 9. Worm; 10. Coupling gear; 101. Screw-type stepper motor; 102. Bearing cover; 103. Oil inlet; 104. Spherical loading head; 105. First oil-resistant sealing gasket; 106. Oil return port; 107. Slit pin; 108. Second oil-resistant sealing gasket; 109. External hexagonal operating part; 110. Y-direction displacement sensor; 111. X-direction displacement sensor. Detailed Implementation

[0029] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0030] It should be noted that, unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "a," "an," or "the," etc., used in the specification and claims of this patent application do not express a limitation on quantity, but rather indicate the presence of at least one; the terms "first," "second," and "third," as used herein, should not be considered as a limitation on the order of components, but are merely for distinguishing different components; the terms "comprising," "including," etc., indicate that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same function.

[0031] To more clearly describe the turbine turning gear loading test device and loading control method, in conjunction with the appendix... Figure 1-11 Description of the embodiment: Example 1 like Figure 1-4 As shown, the present invention discloses a turbine turning gear loading test device. The turning gear loading test device 1 includes a turbine turning gear assembly, a loading execution unit, a current acquisition module, a displacement acquisition module, and a loading control unit.

[0032] See Figure 1 and Figure 2The turbine turning gear assembly targeted by this invention includes bearings 2, worm gear 3, worm gear shaft 4, turning gear cover 5, drive gear 6, turning gear motor 8, and worm 9. Two bearings 2 are installed at the left and right ends of the turning gear cover 5. The two ends of the worm gear shaft 4 are respectively supported in the inner rings of the two bearings 2. The worm gear 3 and the drive gear 6 are both fixed on the worm gear shaft 4. The drive gear 6 meshes with the coupling gear 10 on the turbine. The turning gear motor 8 is installed on the outside of the turning gear cover 5. The motor output shaft of the turning gear motor 8 is fixedly connected to the upper end of the worm 9. The worm 9 meshes with the worm gear 3.

[0033] Two sets of loading execution units are set up, installed on the turbine turning gear assembly and connected to the loading control unit 7. The two sets of loading execution units are distributed opposite to each other at both ends of the worm gear shaft 4, and are used to apply loading force to the worm gear shaft 4 in opposite directions to simulate the real stress state of the turbine rotor under load, so as to realize the load test of the turning gear device.

[0034] The core of the loading execution unit consists of a lead screw stepper motor 101 and a spherical loading head 104. The bearing cover 102 is enclosed at both ends of the worm gear shaft 4 and is fixedly connected to the turning cover 5. The body of the lead screw stepper motor 101 is fixedly installed on the outside of the bearing cover 102. The lead screw output end of the lead screw stepper motor 101 passes through the central through hole of the bearing cover 102 and is fixedly connected to the spherical loading head 104. The lead screw stepper motor 101 drives the spherical loading head 104 to make axial displacement. During the test, the worm gear shaft 4 rotates relative to the spherical loading head 104. The spherical loading head 104 abuts against the shaft end of the worm gear shaft 4 and forms frictional contact to apply axial loading force to the worm gear shaft 4 to form a controlled frictional resistance torque, simulating the rotor load during the start-up and shutdown process of the steam turbine. The axial travel is precisely adjusted by the feed and retraction of the lead screw, thereby adjusting the load on the worm gear shaft 4; an external hexagonal operating part 109 is set at the operating end of the lead screw for manual unloading in case of lead screw stepper motor failure, improving the maintainability and emergency handling capability of the device.

[0035] The screw-type stepper motors 101 of the two sets of loading execution units are assembled with the same specifications. The loading control unit synchronously controls the feed and output of the two sets of screw-type stepper motors 101 to ensure that the two shaft ends of the worm gear shaft 4 are evenly stressed, avoid shaft system jamming due to uneven load, and improve the accuracy of test data.

[0036] The spherical loading head 104 is connected to the output end of the lead screw of the lead screw type stepper motor 101 via a reverse thread. A saddle pin 107 is provided at the connection point to prevent the spherical loading head from loosening or rotating relative to the lead screw. The spherical loading head 104 is enhanced with nitriding / carburizing processes to improve surface wear resistance, achieving a surface hardness of HV800-1200. The spherical loading head 104 employs a spherical structure, forming spherical contact with both ends of the worm gear shaft 4. This adaptively compensates for installation errors and insufficient end face flatness, maintaining good contact and ensuring effective loading. Furthermore, a concave spherical groove adapted to the convex spherical surface of the spherical loading head 104 can be provided on the end face of the worm gear shaft 4 to increase the contact area between the worm gear shaft 4 and the spherical loading head 104, thereby improving loading stability and force conversion efficiency.

[0037] To improve the stability and prevent abnormal noise of the worm gear shaft 4 and the spherical loading head 104 during operation, a lubrication system is provided on the bearing cover 102. Specifically, an oil inlet 103 is provided at the upper part of the bearing cover 102, and an oil return port 106 is provided at the lower part. The lubricating oil is sprayed through the oil inlet 103 to the contact position between the worm gear shaft 4 and the spherical loading head 104, and then discharged from the bearing cover 102 to the external oil tank through the oil return port 106. The flow area of ​​the oil return port 106 is set to 1.1 to 1.3 times the flow area of ​​the oil inlet 103 to ensure smooth return of lubricating oil and avoid oil accumulation and abnormal oil pressure in the oil circuit.

[0038] To ensure the sealing of the lubrication system, a first oil-resistant sealing gasket 105 is provided between the bearing cover 102 and the turning cover 5, and a second oil-resistant sealing gasket 108 is provided between the lead screw stepper motor 101 and the bearing cover 102. The end face is sealed by providing oil-resistant sealing gaskets to prevent lubrication leakage during the test.

[0039] The current acquisition module is connected to the bar gear motor signal, specifically an ammeter, to acquire the three-phase operating current of the bar gear motor 8, with a current acquisition accuracy of ±0.5%FS.

[0040] The displacement acquisition module is used to acquire displacement signals in two mutually perpendicular directions of the worm gear shaft 4. The displacement acquisition module is installed on at least one bearing cover. Each displacement acquisition module includes an X-direction displacement sensor 111 and a Y-direction displacement sensor 110 located on the same cross section of the worm gear shaft 4 and perpendicular to each other. The load control unit generates the shaft center trajectory based on the X-direction and Y-direction displacement signals and determines the meshing state of the worm gear 3 and the worm 9 accordingly.

[0041] The loading control unit, with a PLC as its core, also includes a motor drive module, a displacement signal processing module, a human-machine interface, a one-button start unit, an emergency stop unit, a variable load condition loading control module, and an adaptive loading control module. The loading control unit establishes a closed-loop loading control based on the operating current of the turning gear motor 8, and adjusts the loading process of the lead screw stepper motor 101 according to the shaft trajectory formed by the displacement signal to simulate the variable load conditions during the turbine start-up and shutdown process. When the current or displacement exceeds a set threshold, the loading execution unit is controlled to unload and stop the turning gear operation.

[0042] The motor drive module is connected to two sets of lead screw stepper motors 101, receives control commands from the PLC, and precisely controls the motor's feed, retraction, and position locking, with a position control accuracy of ±0.001mm.

[0043] The displacement signal processing module is connected to the displacement acquisition module to process the displacement signal in real time and transmit it to the PLC. The displacement signal processing module amplifies, filters, and performs A / D conversion on the displacement signal to ensure signal quality.

[0044] The human-machine interface is used for setting loading parameters, setting variable working condition loading curves, setting displacement protection settings, real-time display of operating status, and storing and exporting test data. The human-machine interface uses a color touch screen, making operation intuitive and convenient.

[0045] The one-button start unit is connected to the PLC signal. Pressing the button will directly trigger the preset automatic loading test program, completing the entire process of system self-test, automatic loading, load locking, and data recording in an automated manner, without the need for manual step-by-step operation.

[0046] The emergency stop unit is used for one-button triggering in emergency situations. It can immediately control the lead screw stepper motor to quickly retract and unload, while cutting off the operating circuit of the turning gear motor to ensure the safety of equipment and personnel. The emergency stop unit is implemented by hardware circuitry, with a response time of less than 50ms.

[0047] The variable load control module is used to store and execute preset variable load curves to simulate the actual load changes during the start-up and shutdown of the unit. The variable load control module supports multi-segment curve settings and can simulate complex variable load conditions.

[0048] The adaptive loading control module is used to comprehensively judge the meshing state based on the rate of change of the turning motor current and the displacement sensor signal, and dynamically adjust the loading rate. The adaptive loading control module adopts a fuzzy control algorithm to adjust the loading parameters in real time based on the rate of change of current and displacement signal, so as to realize intelligent loading control.

[0049] During assembly, first, fix the lead screw stepper motor 101 onto the bearing cover 102, with the output end of the lead screw inserted into the central through hole of the bearing cover 102; assemble the spherical loading head 104 to the lead screw output end of the lead screw stepper motor 101 via a reverse thread connection (a thread connection opposite to the working direction of the lead screw), and install a saddle pin 107 to prevent misalignment; weld the external hexagonal operating part 109 to the operating end of the lead screw; after installing the first oil-resistant sealing gasket 105 and the second oil-resistant sealing gasket 108, proceed through... The first fastening screw fixes the bearing cover 102 to the turning cover 5, and the second fastening screw fixes the lead screw stepper motor to the bearing cover 102; the X-direction displacement sensor 111 and the Y-direction displacement sensor 110 are installed in the X and Y direction screw holes of the bearing cover 102 and the signal connection is completed; the loading test device on the other side of the worm gear shaft 4 is installed in the same way, and after completion, the two sets of lead screw stepper motors 101, turning motor, and displacement sensors are all connected to the loading control unit and the signal is calibrated.

[0050] During the test, lubricating oil enters the bearing cover 102 through the oil inlet 103 to lubricate and cool the contact friction surface between the spherical loading head and the worm gear shaft 4, while carrying away the metal debris generated by friction. Finally, it flows back to the test bench oil tank through the oil return port 106 to complete the lubricating oil circulation.

[0051] The automatic test program is triggered by the one-key start unit of the loading control unit. In conjunction with the interlocking control logic of the lead screw stepper motor 101 and the turning gear motor, and the adaptive loading control logic, the loading load is precisely adjusted to realize the automatic test of the turning gear under load, and effectively complete the running-in of the worm gear outer sleeve and the worm.

[0052] During the variable load test, the variable load control module calls the preset variable load curve and automatically adjusts the loading force of the lead screw stepper motor 101 to simulate the actual load changes during the start-up and shutdown of the unit.

[0053] The displacement sensor monitors the displacement of the worm gear shaft 4 in the X and Y directions in real time. After the load control unit processes the displacement signal, it outputs the shaft center trajectory in real time and monitors the meshing of the worm gear 3 and the worm online. When the displacement in the X or Y direction exceeds the protection set value, the shutdown logic is triggered to ensure equipment safety.

[0054] Example 2 like Figure 5-11 As shown, this invention discloses a loading control method based on the above-mentioned turbine turning gear loading test device, comprising the following steps: Preparations before the test: Clean and inspect the turning device to ensure that the inside of the housing is clean and free of debris, burrs, cracks and mechanical damage, and that the transmission and reduction mechanism is engaged normally without abnormal noise; confirm that the manual control lever can be operated freely without any jamming throughout the entire stroke; complete the wiring and no-load test of the turning motor, connect the current acquisition module and complete the signal calibration with the load control unit; complete the installation and calibration of the two displacement sensors in the X and Y directions; complete the connection and flushing of the lubricating oil pipeline of the turning test device, install a filter screen at the oil return port of the oil tank to facilitate subsequent inspection of copper shavings, and prepare red lead powder for tooth surface inspection.

[0055] S1. Establish the target resistance torque and the corresponding variable operating condition loading curve based on the turbine start-up and shutdown conditions.

[0056] To simulate the start-up and shutdown process of a steam turbine unit using a loading execution unit, it is necessary to plot the variable operating condition loading control curves. First, the acceleration, constant speed torque, and acceleration, constant speed, and deceleration loading curves must be obtained. The specific steps are as follows: Step S1.1: Calculate the starting torque. When the turbine rotor shaft system starts, it needs to overcome the resistance torque generated by the friction between it and the four support bearings, i.e., T0=K∑Gi·μi·Ri, where K is the safety factor, generally taken as 1.2, Gi is the rotor weight borne at the bearing, μi is the friction coefficient, and Ri is the shaft radius at each bearing.

[0057] Step S1.2: Calculate the acceleration torque. After startup, based on operating experience, the steam turbine is accelerated to a certain value by a turning gear with a certain angular acceleration, and then runs at a constant speed. Its acceleration torque is T1 = Jα, where J is the total moment of inertia of the steam turbine generator shaft system, which can be directly read from the drawn three-dimensional model. α is the angular acceleration, determined by the ratio of the actual acceleration curve time to the final constant speed rotational speed.

[0058] Step S1.3: Plot the acceleration, constant speed, and deceleration loading curves of the loading execution unit. Based on the actual turbine unit model and operating experience, the acceleration, constant speed, and deceleration turning times for a specific turbine unit can be determined. Specific curves are shown below. Figure 5 As shown, it is divided into the following stages. For example, the total loading curve time is 8 hours, with the acceleration and deceleration processes being relatively short, which can be determined based on the acceleration and deceleration times of a certain turbine unit's turning gear. The remaining time is the constant speed time and the time for automatic torque control changes.

[0059] S1.3.1 First, the loading execution unit applies a certain force F through the lead screw stepper motor 101 after time t1, which is converted into the total torque T0+T1 of the turbine speed-up process through the spherical loading head 104; S1.3.2 Then, start the electric turning gear and maintain the total torque T0+T1 value unchanged for a period of time t2 to simulate the turbine speed-up turning gear process; S1.3.3. By automatically adjusting the control through the loading control unit, after time t3, the total torque drops to T0 and remains unchanged for a period of time t4, simulating the turbine start-up and shutdown process of uniform speed turning. S1.3.4. By automatically adjusting the control through the loading control unit, after time t5, the total torque becomes T0+T1 again, and is maintained for time t6, simulating the turbine shutdown and deceleration turning process.

[0060] S1.3.5 Finally, the total simulated torque is reduced to 0 by automatically adjusting the control unit.

[0061] Based on the calculation results of the loading torque curve above, the selection of the lead screw stepper motor 101 and the spherical loading head 104 was completed, and the test load was determined; the contact stress between the spherical loading head and the worm gear shaft end was calculated to satisfy σ=F / (π·R 2 )≤[σ], where F is the axial load, which can be obtained from the knowledge of force and moment conversion, according to Figure 5 The different torque values ​​in the loading curve are derived from the frictional force generated by the contact area of ​​the spherical loading head 104. R is the radius of the spherical surface of the spherical loading head, and [σ] is the allowable stress of the material.

[0062] S2. Assembly and Pre-inspection of the Device: Fix the turning device on the oil tank of the test bench. Align the lead screw ends of the lead screw type stepper motors 101 of the two sets of loading execution units with the two ends of the worm gear shaft 4 of the turning device. Complete the fixed and sealed assembly of the bearing cover 102 and the turning cover 5. Assemble the spherical loading head 104 to the lead screw output end of the lead screw type stepper motor 101 through reverse thread connection and install the saddle pin 107 to prevent misalignment. Weld the external hexagonal operating part to the tail of the lead screw. Install the X-direction displacement sensor 111 and the Y-direction displacement sensor 110 in the X and Y direction threaded holes of the bearing cover and complete the signal connection. Apply the prepared red lead powder to the tooth surface of the worm gear 3. After manual turning or short-term electric turning, check that the contact spot of the worm gear tooth surface is not less than 55% along the tooth height and not less than 50% along the tooth length. After the meshing meets the requirements, proceed to the next step.

[0063] S3. Control Cabinet (Loading control unit is located inside the control cabinet) Parameter Setting and System Commissioning: First, complete the parameter setting of the target turning gear motor current value and overload protection threshold in the human-machine interface of the loading control unit. Example setting method: the target current is 30%~50% of the rated current of the turning gear motor, and the overload protection threshold is 130% of the target current. According to... Figure 5Complete the variable working condition loading curve setting and the X and Y direction displacement protection setting; then the system performs a self-test. If an abnormality is found during the self-test, the fault point is indicated and the start is locked. After the fault is resolved, the self-test is repeated. After the self-test is normal, the lubricating oil pump is started, and the lubricating oil system is put into normal operation. The lubricating oil is continuously sprayed through the oil inlet 103 of the bearing cover 102 to the contact friction surface between the spherical loading head and the worm gear shaft 4, and the oil pump pressure and return oil are checked to see if they are normal. If the oil pressure or return oil is abnormal, the fault is dealt with and the self-test is repeated. After the oil pressure and return oil are normal, the turning gear motor is started, and the turning gear no-load current and running sound are observed to see if they are normal. If there is an abnormality, the fault is dealt with and the self-test is repeated. When everything is normal, the start-up equipment self-test process is completed. (e.g.) Figure 6 (As shown) S4. Interlocking Automatic Loading Test: After the equipment completes its self-test, the user can select "Adaptive Loading Control" or "Variable Operating Condition Loading Control".

[0064] Adaptive Loading Control: After the adaptive loading control module is triggered, the motor drive module controls the lead screw stepper motor 101 to feed at a set rate, gradually increasing the axial load. The current acquisition module collects the working current of the turning gear motor 8 in real time, and the displacement signal processing module collects the X / Y displacement in real time. The current change rate dI / dt and X / Y displacement of the turning gear motor 8 are fed back to the loading control unit. The loading control unit judges the turning gear engagement state by monitoring the current change rate and X / Y displacement signal in real time: when the current change rate is not greater than ±3% and the X / Y displacement signal is not greater than 0.05mm, the turning gear engagement state is good; when the current change rate is greater than ±3% or the X / Y displacement signal is greater than 0.05mm, the engagement state is abnormal, the system issues an alarm and reduces the loading rate, and continues loading after the system stabilizes; when the current change rate is greater than ±5% or the X / Y displacement signal is greater than 0.1mm, the abnormal shutdown procedure is triggered. Simultaneously, the operating current and target current are compared in real time: when the operating current is lower than the target current, the motor output is slowly increased at the set rate; when the operating current approaches the target current (the difference between the operating current and the target current is less than the preset difference), the feed rate is automatically reduced to decrease the load increase; when the operating current reaches the target current, the load control unit immediately locks the feed position of the lead screw stepper motor, stops the feed, maintains the current load stability, and realizes closed-loop adaptive load control. (e.g.) Figure 10 (As shown) Variable load condition control: Triggering the variable load condition control module, the motor drive module controls the lead screw stepper motor to feed at a set rate, gradually increasing the axial load; according to the preset variable load condition curve... Figure 5The system simulates actual load changes during unit start-up and shutdown, automatically adjusts the loading force, and completes variable operating condition loading tests. A displacement sensor monitors the shaft center trajectory in real time to determine the meshing condition of the worm gear 3 and worm 9. The shaft center trajectory characterizes the meshing state of the worm gear 3 and worm 9. Initially, during the initial loading and break-in period, the shaft center trajectory is a wildly fluctuating peak-and-valley curve. Once meshing is complete, the shaft center trajectory exhibits a regular ellipse or circular shape. The shaft center trajectory curve can be displayed in real time through the human-machine interface of the local control cabinet, allowing for real-time monitoring of the meshing condition of the worm gear 3 and worm 9. (e.g.) Figure 11 (As shown) S5. Stable operation and monitoring: During the operation of the turning gear under load, the current value, oil temperature, motor operating status, X / Y direction displacement, and shaft trajectory are monitored in real time, and a dedicated person is assigned to monitor it.

[0065] Stop the machine every half hour to check the wear of the spherical loading head and the condition of the fasteners. The total loading time should not be less than 8 hours, and the test data should be recorded throughout the process. After the load operation is completed, disassemble and inspect the meshing of the worm gear and worm teeth. Based on the tooth contact spots and wear marks, judge the meshing defects caused by the cumulative errors of machining and assembly. At the same time, check the copper shavings falling through the oil return filter screen of the oil tank.

[0066] S6 shutdown control: Based on different shutdown triggering conditions, it is divided into three processes: normal shutdown, abnormal shutdown, and emergency shutdown.

[0067] Normal shutdown procedure: When the test duration reaches the set value, the lead screw stepper motor retracts to unload the load. After unloading is complete, the turning gear motor is turned off, and the lubrication pump is turned off after 10 minutes. Test data is automatically archived. The turning gear meshing status and wear are manually checked, and the assembly dimensions of the worm gear are adjusted according to the inspection results (e.g., ...). Figure 7 (As shown).

[0068] Abnormal shutdown procedure: The system triggers an abnormal shutdown procedure when any of the following occurs: X / Y direction displacement greater than 0.1mm, current greater than 130% of the set value, or current change rate exceeding ±5% for 10 seconds. At this time, the lead screw stepper motor is quickly unloaded, the rotary motor stops, the lubricating oil pump continues to run, the system automatically records abnormal data, indicates a current fault, and manual inspection of the meshing status and wear is performed. Based on the inspection results, the assembly dimensions of the worm gear are adjusted (e.g., ...). Figure 8 (As shown).

[0069] Emergency Stop Control: The load control unit is equipped with an emergency stop button. Pressing the emergency stop button triggers an abnormal shutdown procedure. After the fault is resolved, the emergency stop button must be manually reset before proceeding to the next step (e.g., ...). Figure 9 (As shown).

[0070] S7 Assembly Dimension Adjustment and Retest: Based on the meshing defects detected by the test, adjust the assembly dimensions of the worm gear and worm shaft accordingly. After the adjustment is completed, repeat the above load test process until the meshing of the worm gear and worm shaft meets the design standards, and complete the archiving of all test data and the final locking of the assembly dimensions.

[0071] The parts not described in detail in the above embodiments are existing technologies.

[0072] It should be noted that although the present invention has been described through the above embodiments, the present invention may have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and modifications to the present invention, but all such changes and modifications should fall within the scope of protection of the appended claims and their equivalents.

Claims

1. A turbine turning gear loading test device, comprising a turbine turning gear assembly, a loading execution unit, and a loading control unit, wherein the turbine turning gear assembly comprises a bearing (2), a worm gear (3), a worm gear shaft (4), a turning gear cover (5), a drive gear (6), a turning gear motor (8), and a worm (9), characterized in that: The loading execution unit is configured as two sets, and the two sets of loading execution units are respectively arranged at both ends of the worm gear shaft (4) and apply axial loading force synchronously towards each other; Each loading execution unit includes a lead screw stepper motor (101), a bearing cover (102), and a spherical loading head (104). The lead screw stepper motor (101) is fixed to the outside of the bearing cover (102), and its lead screw passes through the bearing cover (102) and is fixedly connected to the spherical loading head (104) to drive the spherical loading head (104) to make axial displacement. The spherical loading head (104) abuts against the shaft end of the worm gear shaft (4) and forms frictional contact to apply axial loading force to the worm gear shaft (4) to form a controlled frictional resistance torque, simulating the rotor load during the start-up and shutdown process of the steam turbine. The loading control unit (7) is electrically connected to the turning motor (8), the current acquisition module, the displacement acquisition module and the lead screw stepper motor (101) respectively. The current acquisition module is used to acquire the working current of the turning motor (8), and the displacement acquisition module is used to acquire the displacement signal of the worm gear shaft (4) in two mutually perpendicular directions. The loading control unit (7) establishes a loading closed-loop control based on the working current of the turning motor (8), and adjusts the loading process of the lead screw stepper motor (101) in combination with the shaft center trajectory formed by the displacement signal to simulate the variable working condition load during the start-up and shutdown process of the steam turbine.

2. The turbine turning gear loading test device according to claim 1, characterized in that: The spherical loading head (104) adopts a spherical structure and is connected to the output end of the lead screw of the lead screw stepper motor (101) by reverse thread. The connection part is provided with a saddle pin (107) to prevent the spherical loading head from loosening or rotating relative to each other. The lead screw operating end is provided with an external hexagonal operating part (109) for manual unloading when the lead screw stepper motor fails.

3. The turbine turning gear loading test device according to claim 1, characterized in that: The bearing cover is provided with an oil inlet (103) and an oil return port (106). The flow area of ​​the oil return port (106) is 1.1 to 1.3 times that of the flow area of ​​the oil inlet (103) to form a lubricating oil circulation and carry away friction debris.

4. The turbine turning gear loading test device according to claim 1, characterized in that: A displacement acquisition module is installed on at least one bearing cover; Each displacement acquisition module includes an X-direction displacement sensor (111) and a Y-direction displacement sensor (110) located on the same cross section of the worm shaft (4) and perpendicular to each other.

5. The turbine turning gear loading test device according to claim 1, characterized in that: The end face of the worm gear shaft (4) is provided with a concave spherical groove that matches the convex spherical surface of the spherical loading head (104) to increase the contact area between the two.

6. A loading control method for a turbine turning gear loading test device based on any one of claims 1-5, characterized in that, Includes the following steps: Establish the target resistance torque and the corresponding variable operating condition loading curve based on the turbine start-up and shutdown conditions; Two sets of loading execution units are controlled to apply axial loading force to the worm gear shaft (4) synchronously to form a controlled frictional resistance torque that simulates the turbine rotor load; The working current of the rotating gear motor (8) is collected in real time, and the feed speed and loading position of the loading execution unit are controlled according to the working current to establish a loading closed-loop control. The displacement signals of the worm wheel shaft (4) in two mutually perpendicular directions are collected in real time and the shaft center trajectory is generated. The meshing state of the worm wheel (3) and the worm (9) is determined based on the shaft center trajectory. The loading rate is dynamically adjusted according to the rate of change of the working current of the turning motor (8) and the change of the shaft trajectory, so that the loading process runs according to the variable working condition loading curve. When the operating current, the fluctuation range of the operating current, or the displacement signal exceeds the preset threshold, the control loading execution unit will unload synchronously and stop the turning gear operation.

7. The loading control method according to claim 6, characterized in that: The target resistance torque includes the starting torque generated by overcoming bearing friction resistance and the acceleration torque generated by turning the gear to increase speed. Based on these two, the target resistance torques corresponding to the acceleration loading stage, the uniform loading stage, and the deceleration loading stage are established.

8. The loading control method according to claim 6, characterized in that: The loading closed-loop control includes: increasing the output of the loading execution unit when the working current of the turning motor (8) is lower than the target current; reducing the loading rate when the difference between the working current and the target current is less than the preset difference; and maintaining the loading position to maintain constant loading when the working current reaches the target current.

9. The loading control method according to claim 6, characterized in that: The dynamic adjustment of the loading rate includes: reducing the loading rate or pausing loading when the rate of change of the working current of the turning motor (8) exceeds the set threshold or when the shaft trajectory changes abnormally; and continuing loading when the rate of change of the working current and the shaft trajectory return to stability.

10. The loading control method according to claim 6, characterized in that: After the loading test is completed, the assembly dimensions of the worm wheel (3) and worm (9) are adjusted according to the shaft trajectory, the contact state of the worm gear teeth and the wear debris detection results, and the loading test is repeated until the meshing state meets the preset requirements.

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