High-pressure variable geometry turbine guide vane adjusting mechanism and method based on gear and rack

Abstract

The high-pressure variable geometry turbine guide vane adjusting mechanism comprises a sleeve, the sleeve is connected with an outer casing through an involute spline and used for transmitting power and guaranteeing axial movement of the sleeve, the sleeve is connected with the output end of an electric cylinder, and the output end of the electric cylinder is connected with the gear rack. The axial movement of the sleeve is realized; a sleeve is installed on the inner casing, a rack is installed on the sleeve and meshed with a gear, the gear is fixedly connected with a guide vane shaft, the guide vane shaft is installed between the inner casing and the outer casing, guide vanes are installed on the guide vane shaft, and the sleeve moves to drive the rack and the gear to enable the guide vane shaft to rotate. High-precision adjustment is achieved, the performance of the aero-engine is improved, the structure is compact, reliability is high, and the problems that a traditional adjusting mechanism is complex, low in precision, poor in reliability and the like are effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-pressure turbines for aircraft engines, and in particular relates to a high-pressure variable-geometry turbine guide vane adjustment mechanism and method based on a gear rack. Background Art

[0002] In modern aircraft engines, industrial gas turbines and other advanced power units, the high-pressure turbine is one of the core components, and its performance has a crucial impact on the efficiency, reliability and safety of the entire system. Among them, the angle adjustment of the high-pressure turbine guide vanes is a key technical link in optimizing turbine performance.

[0003] Traditional high-pressure turbine guide vane adjustment mechanisms have many limitations. On the one hand, some adjustment mechanisms use complex hydraulic transmission systems to adjust the guide vane angle. The hydraulic system needs to be equipped with a large number of hydraulic pipelines, valves, oil pumps and other components, which not only makes the structure of the entire adjustment system bloated and increases the volume and weight of the power unit, but also has the risk of leakage in the hydraulic system. Hydraulic oil leakage may pollute the working environment, reduce system efficiency, and even cause safety accidents. In addition, the performance changes of hydraulic oil in high temperature and high pressure environments may affect the adjustment accuracy, requiring complex oil temperature and oil pressure control measures.

[0004] On the other hand, some adjustment mechanisms based on mechanical connecting rods or simple gear transmissions often have low adjustment accuracy. In application scenarios with extremely high performance requirements such as aircraft engines, the need for precise control of the angle of high-pressure turbine guide vanes cannot be met. These traditional mechanical adjustment mechanisms have problems such as clearance and friction during the transmission process, which can easily lead to the accumulation of angle adjustment errors and affect the working efficiency and stability of the turbine. For example, the mechanical connecting rod may become loose due to wear during long-term use, resulting in deviations in the guide vane angle.

[0005] With the continuous development of aerospace technology and the improvement of performance requirements for industrial gas turbines, higher requirements are put forward for the high-pressure turbine guide vane adjustment mechanism, including higher adjustment accuracy, more compact structure, better reliability and stronger ability to adapt to harsh working environments. The existing adjustment mechanism has been unable to meet these growing technical requirements. Therefore, a new type of high-pressure turbine guide vane adjustment mechanism is urgently needed to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to overcome the above technical problems and provide a high-pressure variable-geometry turbine guide vane adjustment mechanism and method based on a gear rack.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack comprises: a sleeve, the sleeve is connected to an outer casing by an involute spline for transmitting power and ensuring the axial movement of the sleeve, the sleeve is connected to the output end of an electric cylinder to achieve the axial movement of the sleeve; a rack is installed on the sleeve, the rack is meshed with a gear, the gear is fixedly connected to a guide vane shaft, the guide vane shaft is installed between the inner casing and the outer casing, the guide vane shaft is installed with a guide vane, and the rack and the gear are driven by the movement of the sleeve to rotate the guide vane shaft.

[0009] Furthermore, it also includes a control system, which is electrically connected to the electric cylinder and is used to accurately control the stroke of the electric cylinder, thereby accurately adjusting the angle of the guide vane shaft. The control system has a feedback adjustment function and adjusts the output of the electric cylinder in real time according to preset parameters and actual operating conditions.

[0010] Furthermore, the guide vane shaft is installed in bearing seats on the inner casing and the outer casing.

[0011] Furthermore, an angle sensor is installed at the bottom of the guide vane shaft to detect the angle of rotation of the guide vane in real time.

[0012] Furthermore, the gear is connected to the guide vane shaft by a key, and the key is one of a flat key, a semicircular key or a spline.

[0013] Furthermore, the electric cylinder is connected to the sleeve via a push rod, and the push rod and the sleeve are rigidly connected.

[0014] Furthermore, it also includes a lubrication system, which includes an oil storage device, an oil pump, an oil pipe and an oil nozzle. The oil storage device stores lubricating oil, and the oil pump transports the lubricating oil to the oil nozzle through the oil pipe.

[0015] Furthermore, the sleeve is provided with a lubrication channel at a key connection portion with the outer casing, and the lubrication channel is connected to an external lubrication system for providing continuous lubrication for the key connection.

[0016] Furthermore, a total temperature and total pressure composite probe is installed on the electric cylinder to reflect the internal temperature and pressure conditions.

[0017] The present invention also includes:

[0018] A method for adjusting the high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack as described above, the method comprising:

[0019] Sending a control command to the electric cylinder through the control system to start the electric cylinder to push the sleeve to move axially;

[0020] The sleeve drives the rack to move, and the rack drives the gear meshing therewith to rotate;

[0021] The gear drives the guide vane shaft to rotate, thereby changing the angle of the guide vane shaft installed on the inner casing and the outer casing, thereby adjusting the guide vane angle; during the adjustment process, real-time monitoring and feedback adjustment are performed by the control system to ensure the accuracy and stability of the guide vane angle adjustment.

[0022] The beneficial effects of the present invention are:

[0023] The present invention realizes high-precision adjustment, improves the performance of aircraft engines, and has a compact structure and high reliability, effectively solving the problems of complex, low-precision and poor reliability of traditional adjustment mechanisms. A method for adjusting the angle of high-pressure turbine guide vanes using the adjustment mechanism is also provided, and the control system controls the stroke of the electric cylinder to achieve adjustment of the guide vanes with a maximum adjustment angle of 1.5° and an accuracy of 0.1°. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Attached Figure 1 It is a structural schematic diagram of the present invention.

[0025] Attached Figure 2 It is an exploded view of the present invention.

[0026] Attached Figure 3 It is a connection diagram of the gear rack of the present invention.

[0027] Attached Figure 4 It is a schematic diagram of the cooperation between the outer casing and the sleeve of the present invention.

[0028] Attached Figure 5 It is a structural schematic diagram of the guide vane of the present invention.

[0029] Attached Figure 6 It is a structural schematic diagram of the electric cylinder of the present invention.

[0030] In the attached drawings: 1. gear, 2. rack, 3. sleeve, 3-1. internal spline, 3-2. rack mounting hole, 4. outer casing, 4-1. blade mounting hole, 4-2. external spline, 5. electric cylinder, 6. total temperature and total pressure composite probe, 7. guide vane, 7-1. guide vane shaft, 7-2. guide vane shaft keyway, 8. inner casing, 8-1. blade mounting hole, 9. angle sensor. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the accompanying drawings.

[0032] Embodiment 1:

[0033] The present invention provides a high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack, which comprises: a gear 1, a rack 2, a sleeve 3, an outer casing 4, an electric cylinder 5, a total temperature and total pressure composite probe 6, a guide vane 7, and an inner casing 8;

[0034] As attached Figure 1-6 As shown, the sleeve 3 is connected to the outer casing 4 by a key, which is used to transmit power and ensure the axial movement of the sleeve 3. The sleeve 3 is connected to the output end of the electric cylinder 5 to realize the axial movement of the sleeve 5; a rack 2 is installed on the sleeve 5, and the rack 2 is meshed with the gear 1. The gear 1 is fixedly connected to the guide vane shaft 7-1, and the guide vane shaft 7-1 is installed between the inner casing 8 and the outer casing 4. A guide vane 7 is installed on the guide vane shaft 7-1, and the rack 2 and the gear 1 are driven by the movement of the sleeve 3 to rotate the guide vane shaft 7-1.

[0035] The guide vane shaft 7 - 1 is installed in the bearing seats on the inner casing 8 and the outer casing 4 .

[0036] Preferably, the sleeve 3 and the outer casing 4 are connected via an involute spline.

[0037] Preferably, in order to achieve axial movement of the sleeve without radial displacement, the outer casing 4 and the sleeve 3 are connected by internal splines 3-1 and external splines 4-2. At the same time, in order to prevent jamming during movement, the splines can be selected to have an inclined angle.

[0038] This embodiment also includes a control system, which is electrically connected to the electric cylinder 5 and is used to accurately control the stroke of the electric cylinder 5, thereby accurately adjusting the angle of the guide vane shaft 7-1. The control system has a feedback adjustment function and adjusts the output of the electric cylinder 5 in real time according to preset parameters and actual operating conditions.

[0039] In this embodiment, an angle sensor 9 is installed at the bottom of the guide vane shaft 7-1 to detect the rotation angle of the guide vane 7 in real time.

[0040] In this embodiment, the gear 1 and the guide vane shaft 7-1 are connected by a key, and the key is one of a flat key, a semicircular key or a spline, and the matching accuracy between the key and the keyway is above ±0.001.

[0041] Preferably, the electric cylinder 5 in this embodiment is connected to the sleeve 3 via a push rod, the push rod and the sleeve 3 are rigidly connected, and the connection part is reinforced to withstand the thrust of the electric cylinder. The connection part can be made of high-strength alloy steel and reinforced by welding, bolt connection, etc. to ensure that it can withstand the maximum thrust of the electric cylinder without deformation or loosening.

[0042] Preferably, the mounting surface on the sleeve 3 for mounting the rack in this embodiment is a precision-machined plane, and the flatness tolerance is within the range of ±0.001 to ensure the accuracy and stability of the rack installation.

[0043] The sleeve 3 is manufactured by precision casting or forging process using high-strength, high-temperature-resistant and wear-resistant alloy materials (such as nickel-based alloys). The outer surface of the sleeve 3 is processed to form an involute spline shape with a module of three required for spline connection with the outer casing 4. The tooth profile accuracy, pitch accuracy and surface roughness of the spline should meet the requirements of high-precision transmission (tooth profile error is less than 0.01mm, pitch error is less than 0.01mm, and surface roughness Ra is less than 0.2μm).

[0044] Preferably, in this embodiment, the rack 2 and the gear 1 are both made of high-strength alloy steel. The processing of the rack 2 includes steps such as forging, rough machining, heat treatment and finishing. During the heat treatment process, the hardness of the tooth surface of the rack 2 is made to reach a requirement higher than 63HRC. Quenching, tempering and other processes can be used, and the process parameters are strictly controlled to ensure the uniformity of hardness. During finishing, the tooth surface roughness is reduced to less than Ra0.8 through a grinding process, and the modulus, pressure angle and other parameters of the rack 2 are ensured to be accurately matched with the gear.

[0045] Preferably, the guide vane 7 shaft in this embodiment is made of high-strength, high-temperature resistant materials, and its structure should meet the requirements of connecting with the gear 1 and installing the guide vane. At the part where the guide vane shaft 7-1 is connected to the gear, the spline or keyway is finely processed to ensure the coaxiality and matching accuracy of the connection with the gear. The connection method between the guide vane shaft 7-1 and the guide vane should ensure that the torque can be transmitted stably, so that the guide vane 7 can rotate synchronously with the guide vane shaft 7-1.

[0046] Preferably, in the involute spline connection between the sleeve 3 and the outer casing 4 in this embodiment, the centering method of the spline is tooth side centering, and the tooth side clearance of the spline is in the range of 0.005-0.02, so as to ensure that the sleeve moves smoothly in the outer casing and transmits stable torque.

[0047] Preferably, the modules and pressure angles of the rack and gear in this embodiment match, the gear tooth surface hardness is required to reach 63-65HRC, the core hardness of the gear is between 30-45HRC, the rack tooth surface hardness reaches 60-65HRC, and the rack matrix hardness is 30-40HRC. The back of the rack 2 can be selected to have a certain slope to achieve the purpose of reducing weight.

[0048] Preferably, the housing of the electric cylinder 5 in this embodiment is provided with a heat dissipation structure, and the heat dissipation structure is a heat sink or an air cooling channel to ensure that the temperature of the electric cylinder during operation is within a normal operating temperature range.

[0049] In this embodiment, the regulating mechanism further includes a lubrication system, which includes an oil storage device, an oil pump, an oil pipe and an oil injector. The oil storage device stores lubricating oil, and the oil pump transports the lubricating oil to the oil injector through the oil pipe.

[0050] The sleeve 3 is provided with a lubrication channel at the spline connection portion with the outer casing 4 , and the lubrication channel is connected to an external lubrication system for providing continuous lubrication for the spline connection.

[0051] In this embodiment, the outer casing 4 is installed at the corresponding position of the turbine engine, and a high-precision positioning tool is used to ensure the installation angle and position accuracy of the outer casing. The outer casing is fixed to the engine structure by bolts, and the specifications, strength grade and tightening torque of the bolts should be strictly controlled according to the design requirements to ensure the stability of the outer casing 4 during operation.

[0052] The method for adjusting the high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack described in this embodiment includes:

[0053] Sending a control command to the electric cylinder 5 through the control system to start the electric cylinder 5 to push the sleeve 3 to move axially;

[0054] The sleeve 3 drives the rack 2 to move, and the rack 2 drives the gear 1 meshing therewith to rotate;

[0055] The gear 1 drives the guide vane shaft 7-1 to rotate, thereby changing the angle of the guide vane shaft 7-1 installed on the inner casing 8 and the outer casing 4, thereby adjusting the angle of the guide vane 7; during the adjustment process, real-time monitoring and feedback adjustment are performed by the control system to ensure the accuracy and stability of the guide vane 7 angle adjustment.

[0056] Embodiment 2:

[0057] According to the gear rack-based high-pressure variable-geometry turbine guide vane adjustment mechanism described in Example 1, the assembly process is as follows:

[0058] Combined with Figure 1-2 To illustrate, the inner casing 8 and the outer casing 4 are assembled. During the assembly process, a sealing structure (rubber sealing ring or metal sealing gasket) is first installed on the joint surface, and then the inner casing 8 is aligned with the outer casing 4 using a special assembly tool, and then slowly closed and fixed with bolts. When tightening the bolts, they should be tightened step by step according to the prescribed sequence and torque to ensure the sealing of the joint surface and the overall structural strength of the inner casing 8 and the outer casing 4.

[0059] Install the guide vane shaft 7-1 into the bearing seats on the inner and outer casings 4. Before installation, clean, lubricate and inspect the bearings to ensure that the quality and performance of the bearings meet the requirements. Use a special installation tool to slowly insert the guide vane shaft 7-1 into the bearing seat to avoid damage to the bearings and journals. After installation, check the rotation flexibility and axial movement of the guide vane shaft 7-1 to ensure that they are within the specified range.

[0060] Install the processed gear 1 on the guide vane shaft 7-1, using a key connection method. When installing the key, ensure the matching accuracy between the key and the keyway to prevent loosening during operation. After installation, check the connection firmness between the gear 1 and the guide vane shaft 7-1. This can be checked by applying a certain torque to ensure that no relative displacement occurs within the normal working torque range.

[0061] After applying a proper amount of grease or other suitable lubricant to the spline part of the sleeve 3, the sleeve 3 is installed on the outer casing 4 through the spline connection. During the installation process, pay attention to the installation direction and position of the sleeve 3 to ensure that it can slide smoothly on the spline. After the installation is completed, check the axial movement flexibility of the sleeve 3, and there should be no jamming phenomenon. At the same time, check the matching of the spline to ensure that good connection and transmission performance can be maintained throughout the entire movement stroke.

[0062] Install the rack 2 on the pre-machined mounting surface on the sleeve 3, and use positioning pins or other positioning devices to ensure that the rack 2 is accurately installed. During installation, the rack can be fixed to the sleeve 3 using appropriate clamping devices, and then permanently fixed by bolts or welding to ensure that the rack will not move relative to the sleeve during operation.

[0063] like Figure 4 As shown, after the rack 2 is installed, move the sleeve 3 assembly with the rack 2 to the position where it meshes with the gear 1, and check the meshing of the rack 2 and the gear 1. The meshing clearance is required to be uniform and the tooth surface is in good contact. If necessary, the meshing state can be adjusted by fine-tuning the position of the sleeve 3 to ensure the smoothness and accuracy of the transmission.

[0064] Move the electric cylinder 5 to the position corresponding to the sleeve 3, so that the push rod of the electric cylinder 5 is accurately connected with the connection structure of the sleeve 3. During the connection process, a guide device can be used to ensure that the push rod can be smoothly inserted into the connection part of the sleeve. After the connection is completed, check the firmness and coaxiality of the connection to ensure that the thrust of the electric cylinder 5 can be accurately transmitted to the sleeve 3 without generating eccentric load.

[0065] Embodiment 3:

[0066] According to the gear rack-based high-pressure variable geometry turbine guide vane adjustment mechanism described in embodiment 1 or 2, as shown in the attached Figure 1As shown, after the assembly is completed, first perform a visual inspection of the entire adjustment mechanism to ensure that each component is installed correctly without looseness, interference, etc. Check the lubrication system to ensure that the lubrication channel is unobstructed and the lubricant is evenly distributed to each part that needs lubrication (such as splines, the meshing point between gear 1 and rack 2, etc.). Place the adjustment mechanism in the initial position, use measuring tools (such as angle measuring instruments, displacement sensors, etc.) to check the initial angles of the guide vane shaft 7-1 and the guide vane 7, and compare them with the initial angles required by the design. The error should be controlled within the range of ±0.05°. At the same time, check the initial position of the push rod of the electric cylinder 5, read the stroke data of the electric cylinder through the control system, and ensure that it matches the initial position setting value.

[0067] Start the electric cylinder 5 without loading, and make the push rod of the electric cylinder perform slow telescopic movement through the control system, and observe the movement of the sleeve 3, rack 2, gear 1 and guide vane shaft 7-1. Check whether the axial movement of the sleeve on the spline is smooth and whether there is abnormal vibration or noise; observe whether the meshing transmission between the rack 2 and the gear 1 is smooth, and whether there is abnormal wear or jamming on the tooth surface; check whether the rotation of the guide vane shaft 7-1 is flexible and whether there is axial movement or abnormal resistance. During the entire movement process, use sensors to monitor the stroke and speed of the push rod of the electric cylinder 5 and the angle change of the guide vane shaft 7-1 in real time, record the data and compare it with the preset values ​​of the control system, and make preliminary adjustments to the parameters of the control system to ensure the accuracy and stability of the movement.

[0068] After the no-load debugging is completed and everything is normal, the adjustment mechanism is loaded and debugged. The electric cylinder 5 can be started again to perform the adjustment operation by simulating the load condition when the turbine is working. In the loaded state, the performance changes of the adjustment mechanism when it is under load are mainly checked, including whether the thrust of the electric cylinder 5 can meet the adjustment requirements, the strength and wear resistance of the transmission part under load, and the control system's ability to ensure the adjustment accuracy under load interference. According to the debugging results, the various components of the adjustment mechanism and the control system are further optimized and adjusted, such as adjusting the output power of the electric cylinder 5, optimizing the parameters in the control algorithm, etc.

[0069] After loading and debugging, the adjustment accuracy of the adjustment mechanism is finally calibrated. Use high-precision angle measurement equipment and displacement sensors to accurately measure the angle of the guide vane shaft 7-1 and the push rod stroke of the electric cylinder 5 at different set angles. Compare the measurement results with the angle-stroke correspondence required by the design, and fine-tune the parameters in the control system so that the adjustment mechanism can achieve the specified adjustment accuracy within 0.1° throughout the entire adjustment range. After the calibration is completed, the entire adjustment mechanism is repeatedly tested to ensure the stability and reliability of the accuracy.

[0070] Error affects synchronization analysis:

[0071] (1) Influence of clearance error of electric cylinder transmission components: The clearance of the transmission mechanism inside the electric cylinder is controlled within a certain range. If the clearance is too large, the push rod will move inaccurately during movement, affecting the axial movement accuracy of the sleeve, and further affecting the meshing transmission of the rack and gear, causing errors in the guide vane angle adjustment. For example, when the electric cylinder pushes the sleeve, the clearance may cause the actual stroke of the push rod to be inconsistent with the stroke commanded by the control system, and the rotation angle transmitted to the gear will deviate from the expected value.

[0072] (2) Influence of sleeve spline machining accuracy error: The outer surface of the sleeve is connected to the outer casing spline. If the tooth profile accuracy, pitch accuracy and surface roughness of the spline do not meet the requirements, the axial movement smoothness of the sleeve on the spline will be affected. For example, if the tooth profile error is too large, the sleeve may have radial offset or jamming during movement, making the meshing state of the rack and gear unstable, causing guide vane angle adjustment errors, and also reducing the stability of the spline torque transmission.

[0073] (3) Influence of meshing error between rack and gear: If the modulus, pressure angle and other parameters of rack and gear are not accurately matched, or the meshing clearance is uneven and the tooth surface contact is poor, it will cause impact and vibration during the transmission process, affecting the smoothness and accuracy of gear rotation, and ultimately leading to guide vane angle adjustment error. For example, if the meshing clearance is too large, there will be idle travel during transmission, causing the guide vane rotation angle to deviate; poor tooth surface contact will cause uneven force on the gear, accelerate tooth surface wear, and further affect transmission accuracy.

[0074] Guide vane synchronization is achieved by:

[0075] (1) Manufacturing and installation of high-precision components:

[0076] a. Gear and guide vane shaft connection: The gear and guide vane shaft are connected by a key, and the key type is one of a flat key, a semicircular key or a spline, and the matching accuracy of the key and the keyway is above a certain level. When machining the connection between the guide vane shaft and the gear, the spline or keyway is finely machined to ensure the coaxiality and matching accuracy of the connection, so that the guide vane shaft can rotate synchronously with the gear, thereby ensuring the synchronous rotation of the guide vane and the guide vane shaft.

[0077] b. Spline connection between sleeve and outer casing: The sleeve and outer casing are connected by involute spline, the centering method of spline is tooth side centering, and the tooth side clearance is within the range of 0.005-0.02. This connection method can not only transmit power, but also ensure smooth and stable axial movement of the sleeve, so that when the sleeve drives the rack to move, it can stably drive the gear to rotate, thereby realizing synchronous adjustment of the guide vane.

[0078] c. Rack installation: The rack is installed on the sleeve, and the installation plane is a precision-machined plane with a flatness tolerance within a certain range to ensure the accuracy and stability of the rack installation. During installation, use positioning pins or other positioning devices to ensure the accurate position of the rack, and use clamping devices to fix it and permanently fix it by bolts or welding to ensure that the rack will not move relative to the sleeve during operation, thereby ensuring the stability of the gear meshing transmission and facilitating the synchronization of the guide vanes.

[0079] (2) Control system collaborative work:

[0080] a. Accurately control the stroke of the electric cylinder: The control system is electrically connected to the electric cylinder and can accurately control the stroke of the electric cylinder. Through preset parameters and feedback adjustment functions, the output of the electric cylinder is adjusted in real time according to the actual operating conditions to ensure that the electric cylinders corresponding to each guide vane move in a coordinated manner, thereby achieving synchronous adjustment of the guide vanes. For example, when the guide vane angle needs to be adjusted, the control system sends the same stroke instruction to each electric cylinder, so that each electric cylinder pushes the sleeve to move the same distance, thereby driving the gear and the guide vane shaft to rotate synchronously to achieve guide vane synchronization.

[0081] b. Angle sensor feedback: An angle sensor is installed at the bottom of the guide vane shaft, which can reflect the angle of the guide vane rotation in real time. The control system monitors and compares the angles of each guide vane based on the feedback information from the angle sensor. If it is found that the angle of a guide vane is inconsistent with other guide vanes, the output of the corresponding electric cylinder can be adjusted in time to make the guide vane angles consistent and ensure synchronous adjustment. During the adjustment process, the actual angle of each guide vane is constantly compared with the preset angle, and the stroke of the electric cylinder is fine-tuned to achieve high-precision synchronous control.

[0082] The inner casing diameter is 520mm, the outer casing diameter is 740mm, and the guide vane length is between 80-100mm. According to the formula And L = rθ, where θ is the guide vane rotation angle, x is the push rod distance, m is the gear rack module, and z is the number of gear teeth. It can be concluded that if the guide vane rotates 1.2-1.5°, the gear rotation range is 0.2093-0.2618 rad.

[0083] The formula for the relationship between the push rod distance and the guide vane angle is derived as follows:

[0084] Principle analysis: The electric cylinder pushes the sleeve to move, and the rack on the sleeve drives the gear to rotate, thereby rotating the guide vane shaft to adjust the guide vane angle. Suppose the moving distance of the electric cylinder push rod is x, and the change in the guide vane angle is θ.

[0085] Key parameters: The module of the rack on the sleeve is m, the pressure angle is α, and the number of gear teeth is z.

[0086] Formula derivation process: The linear displacement of the rack is equal to the arc length of the gear. According to the arc length formula L = rθ (here is the gear pitch circle radius, ), we can get

[0087] Then the relationship between the guide vane angle θ and the push rod distance x is:

[0088] Derive the relationship between intake volume and push rod distance:

[0089] Principle analysis: The change of guide vane angle will affect the intake volume of the turbine. There is a certain functional relationship between the guide vane angle and the intake volume. Combined with the relationship between the guide vane angle and the push rod distance derived above, the relationship between the intake volume and the push rod distance is obtained. Assume that the intake volume is Q, the guide vane angle is θ, and the push rod distance is x.

[0090] Key parameters: The turbine's intake flow coefficient is C, the intake area is A, the intake velocity is v, the initial installation angle of the guide vane is θ0, and the coefficient of the influence of the change in the guide vane angle on the intake volume is k (related to the turbine structure and working characteristics).

[0091] Formula derivation process:

[0092] The intake volume Q = C × A × v. The change in the guide vane angle will change the intake velocity v. Assume v = v0 (1 + kθ), where v0 is the intake velocity at the initial angle of the guide vane.

[0093] Then Q = C×A×v0(1+kθ).

[0094] Depend on Substituting into the above formula, we can get the relationship between the intake volume and the push rod distance: Q = C × A × v0 (1 + kθ).

[0095] In the high-pressure variable-geometry turbine guide vane adjustment mechanism, the rack has a movable joint that can effectively compensate for the errors generated during the manufacturing and installation processes, ensuring that the rack and gear always maintain a good meshing state and avoiding poor meshing caused by the accumulation of small deviations, thereby improving the stability and reliability of the transmission, reducing vibration and noise, and extending the service life of components.

[0096] Ceramic matrix composites, such as silicon carbide (SiC) ceramic matrix composites, generally have a density of 3.0-3.2 g / cm 3 .

[0097] Bending strength: can reach 300-500MPa or even higher, able to withstand certain mechanical stress.

[0098] Thermal conductivity: between 10-50W / (m·K), with good thermal conductivity, which is conducive to heat dissipation and avoids local overheating.

[0099] Thermal expansion coefficient: relatively low, usually 4-5×10 -6 / ℃, it can maintain good dimensional stability in high temperature environment and reduce deformation and stress caused by thermal expansion and contraction.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack, characterized in that: include: A sleeve (3), wherein the sleeve (3) is connected to an outer casing (4) via a key for transmitting power and ensuring the axial movement of the sleeve (3), and the sleeve (3) is connected to the output end of an electric cylinder (5) to achieve the axial movement of the sleeve (5); a rack (2) is mounted on the sleeve (5), the rack (2) is meshed with a gear (1), the gear (1) is fixedly connected to a guide vane shaft (7-1), the guide vane shaft (7-1) is mounted between an inner casing (8) and an outer casing (4), and a guide vane (7) is mounted on the guide vane shaft (7-1), and the movement of the sleeve (3) drives the rack (2) and the gear (1) to rotate the guide vane shaft (7-1).

2. The high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to claim 1, characterized in that: The invention also comprises a control system, which is electrically connected to the electric cylinder (5) and is used to accurately control the stroke of the electric cylinder (5), thereby accurately adjusting the angle of the guide vane shaft (7-1); the control system has a feedback adjustment function, and adjusts the output of the electric cylinder (5) in real time according to preset parameters and actual operating conditions.

3. The high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to claim 1, characterized in that: The guide vane shaft (7-1) is installed in bearing seats on the inner casing (8) and the outer casing (4).

4. The high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to claim 1 or 3, characterized in that: An angle sensor (9) is installed at the bottom of the guide vane shaft (7-1) to detect the rotation angle of the guide vane (7) in real time.

5. The high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to claim 4, characterized in that: The gear (1) and the guide vane shaft (7-1) are connected by a key, and the key is one of a flat key, a semicircular key or a spline.

6. The high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to claim 1, characterized in that: The electric cylinder (5) is connected to the sleeve (3) via a push rod, and the push rod and the sleeve (3) are rigidly connected.

7. The high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to claim 1, characterized in that: It also includes a lubrication system, which includes an oil storage device, an oil pump, an oil pipe and an oil injection nozzle. The oil storage device stores lubricating oil, and the oil pump transports the lubricating oil to the oil injection nozzle through the oil pipe.

8. The high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to claim 7, characterized in that: The sleeve (3) is provided with a lubrication channel at the key connection portion with the outer casing (4), and the lubrication channel is connected to an external lubrication system to provide continuous lubrication for the key connection.

9. The high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to claim 1, characterized in that: The electric cylinder (5) is equipped with a total temperature and total pressure composite probe (6) for reflecting the internal temperature and pressure conditions.

10. A method for adjusting a high-pressure variable-geometry turbine guide vane adjustment mechanism based on a gear rack according to any one of claims 1 to 9, characterized in that: The method includes: Sending a control instruction to the electric cylinder (5) through the control system, starting the electric cylinder (5) to push the sleeve (3) to move axially; The sleeve (3) drives the rack (2) to move, and the rack (2) drives the gear (1) meshing therewith to rotate; The gear (1) drives the guide vane shaft (7-1) to rotate, thereby changing the angle of the guide vane shaft (7-1) installed on the inner casing (8) and the outer casing (4), thereby adjusting the angle of the guide vane (7); during the adjustment process, real-time monitoring and feedback adjustment are performed by the control system to ensure the accuracy and stability of the guide vane (7) angle adjustment.

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