Supercharger turbine
By optimizing the turbocharger turbine blade structure and increasing the natural frequency of vibration, the problem of blade resonance in the existing technology has been solved, resulting in improved cost-effectiveness and reduced failures.
Patent Information
- Application Number
- CN202423290661.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2034-12-30
AI Technical Summary
In existing technologies, methods for reducing the excitation force of turbocharger turbine blades are complex and costly, and it is difficult to effectively avoid blade resonance.
By optimizing the turbocharger turbine blade structure and increasing its natural vibration frequency, the blades can avoid the excitation force frequency. The design improvements include adjusting the blade angle, thickness, and chamfer, and the optimization is carried out using simulation methods.
This effectively avoids blade resonance, reduces the occurrence of failures, improves the overall reliability and vibration resistance of the turbine, and lowers the cost of improvement.
Smart Images
Figure CN223825065U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to turbocharger technical field especially relates to a kind of turbocharger turbine. BACKGROUND
[0002] With the improvement of engine performance, the failure problem of key components of engine is increasingly prominent, and the failure of turbocharger, as one of the core components of engine, will seriously affect the function and performance of engine. The failure of turbocharger is mostly caused by low-cycle fatigue fracture and high-cycle fatigue fracture of blade. High-cycle fatigue fracture, also known as stress fatigue damage, is mainly caused by fatigue fracture of blade resonance, and the main reason for causing resonance is that the natural frequency of blade is equal to or an integer multiple of the excitation frequency in the working environment, which causes the blade to produce a large amplitude of vibration response. After a certain number of stress cycles, fatigue cracks appear on the blade and eventually lead to fracture.
[0003] The excitation source of turbine blade is mainly caused by uneven inlet air of turbine blade, and the formation reason of periodic excitation force of turbine blade is relatively complex, which is mainly related to uneven ignition of engine cylinder, exhaust manifold connection mode, volute inlet flow passage form, volute nozzle ring blade and other factors. From the perspective of excitation source, it is difficult to improve high-cycle fatigue fracture of turbine at a large cost and for a long period.
[0004] In order to avoid the risk of blade resonance of turbocharger turbine, the common improvement measures include increasing the natural frequency of blade vibration, reducing the excitation force of blade and improving the anti-vibration performance of blade. In the prior art, the excitation force of blade is mainly considered from the perspective of excitation source, and the technical means is relatively complex and the improvement cost is relatively high. Therefore, it is necessary to provide a method for optimizing the natural frequency of turbocharger turbine to solve or at least alleviate the above-mentioned defects. SUMMARY
[0005] The main purpose of the utility model is to provide a kind of turbocharger turbine, to solve the technical problem that the natural frequency of blade vibration is mainly considered from the perspective of excitation source in the prior art, and the technical means is relatively complex and the improvement cost is relatively high.
[0006] To achieve the above-mentioned purpose, the utility model provides a kind of turbocharger turbine, including wheel back, center hub, second blade and rotor shaft, the center hub is arranged at one side of the wheel back, the rotor shaft, the wheel back and the center hub are coaxially arranged and fixedly connected, the second blade is arranged between the center hub and the wheel back, the center hub, the wheel back and the adjacent two second blades form turbine airflow channel, the turbine airflow channel has radial inlet arranged close to the wheel back and axial outlet arranged close to the first trailing edge of the second blade, the included angle between the second trailing edge line of the second blade and the radial plane is β, and the value range of β is 10°-11°.
[0007] Further, the eleven groups of the second blades are evenly spaced in the circumferential direction.
[0008] Further, the wheel back is a star-shaped disc back structure, and the second blades are arranged on the outer convex lugs of the wheel back.
[0009] Further, the value of β is 10.8°.
[0010] Further, the thickness of the second blades gradually increases in the direction of the radial inlet towards the axial outlet.
[0011] Further, the blade root chamfer radius gradually decreases in the direction of the radial inlet towards the axial outlet.
[0012] Further, the rotor shaft is inserted into the central hub and is interference-fitted with the central hub.
[0013] Further, the effective blade height of the second blade is 9.8 mm.
[0014] Compared with the prior art, the supercharger turbine has the following beneficial effects:
[0015] The supercharger turbine is designed and improved based on the blade structure, improves the vibration natural frequency of the turbine blade, avoids the vibration natural frequency of the turbine blade from the frequency of the exciting force, so that the turbine blade does not resonate, reduces the occurrence of turbine blade failure, and solves the technical problems that the prior art mainly considers improving the vibration resistance of the turbine blade from the angle of the exciting source, and the technical means is relatively complex and the improvement cost is relatively high. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in these drawings without creative labor.
[0017] Figure 1 It is a structural schematic diagram of the prior art before the optimization of the supercharger turbine;
[0018] Figure 2 It is a flowchart of the method for optimizing the natural frequency of the supercharger turbine in an embodiment of the present application;
[0019] Figure 3 It is an optimization process schematic diagram in an embodiment of the present application;
[0020] Figure 4It is a structural schematic view of the optimized supercharger turbine in an embodiment of the utility model;
[0021] Figure 5 It is a structural schematic view of the optimized supercharger turbine in an embodiment of the utility model;
[0022] Figure 6 It is a structural schematic view of the optimized supercharger turbine in an embodiment of the utility model;
[0023] Figure 7 It is a test flow schematic view of the first order vibration natural frequency.
[0024] Legend:
[0025] 100, supercharger turbine;10, back of wheel;20, center hub;30, second blade;31, second tail edge line;311, tail edge starting point;312, tail edge termination point;313, blade root chamfer;40, turbine airflow channel;501, first tail edge;502, cusp.
[0026] The utility model realizes, function characteristics and advantages will be further explained with reference to the drawings in combination with embodiments. DETAILED DESCRIPTION
[0027] It should be understood that the specific embodiments described herein are merely intended to explain the utility model, and are not intended to limit the utility model.
[0028] The technical solutions in the embodiments of the utility model will be clearly and completely described in combination with the drawings in the embodiments of the utility model. Apparently, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.
[0029] It should be noted that all directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the utility model are only used to explain the relative position relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), if the specific posture changes, the directionality indications also change accordingly.
[0030] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.
[0031] Please refer to the attached Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 , the present application provides a kind of method for optimizing the inherent frequency of supercharger turbine, and the supercharger turbine before optimization includes wheel disc, rotor shaft and first blade, the rotor shaft is coaxially arranged with the wheel disc, the first blade is arranged on the wheel disc and is arranged in spiral, adjacent two first blade and the wheel disc form turbine airflow passage between, comprising the steps of: determining the first tail edge of the first blade at turbine outlet position is cut off the bevel line, the bevel line has bevel start point and bevel end point, the bevel start point is at the position of the maximum diameter of the profile line of first tail edge Point 502 position is inwardly biased α along axial direction, the included angle of the bevel line relative to radial plane is β, and the bevel end point is at the root fillet position of first blade;The side of the bevel line towards axial gas outlet is cut off to form the supercharger turbine after optimization.
[0032] The method for optimizing the inherent frequency of supercharger turbine provided by the present application improves the vibration inherent frequency of the first blade of the supercharger turbine before optimization, avoids the frequency of the first blade vibration inherent frequency of turbine from the exciting force, so that the first blade does not resonate, reduces the occurrence of first blade failure, solves the technical problems that the prior art mainly considers reducing the first blade exciting force from the exciting source, the technical means is more complex, and the improvement cost is higher. When optimizing, the bevel start point of cutting first tail edge and the slope of bevel line are determined, and the bevel end point is located at the root fillet position of first blade, and the weak part of the first tail edge of the existing supercharger turbine before optimization is cut off to form the supercharger turbine after optimization.
[0033] Further, the wheel disc comprises a center hub and a wheel back, the center hub is arranged above the wheel back, the rotor shaft, the wheel back and the center hub are coaxially arranged, the first blade is arranged between the center hub and the wheel back, the turbine airflow channel has a radial inlet arranged close to the wheel back and an axial outlet arranged close to the first blade tail edge, and eleven groups of the first blades are arranged in a circumferential direction.
[0034] Further, the value of alpha ranges from 1.0 to 2.0 millimeters, and the value of beta ranges from 10° to 11°.
[0035] Further, the value of alpha is 1.5 millimeters, and the value of beta is 10.8°.
[0036] Further, the thickness of the first blade gradually increases in the direction of the radial center axis. In the utility model, the radial outer edge of the first blade gradually thickens and extends to the blade root position, and the maximum thickness of the radial outer edge of the first blade is 0.6 mm.
[0037] Further, the blade root chamfer radius gradually decreases in the direction from the radial inlet to the axial outlet. In the utility model, the inlet blade root chamfer radius of the first blade is 1.8 mm, the outlet blade root chamfer radius of the first blade is 1.2 mm, and the blade root chamfer is a variable chamfer design.
[0038] Further, the effective blade height of the first blade is 9.8 mm.
[0039] Further, the inlet geometric angle of the first blade is 0°, and the outlet geometric angle of the first blade is 63.8°.
[0040] Further, the step of "cutting off the side close to the outlet of the bevel to form a new supercharger turbine" specifically comprises:
[0041] The two ends of the rotor shaft of the supercharger turbine before optimization are clamped and fixed through a dividing head;
[0042] Based on the bevel, grinding is carried out on a cylindrical grinder, and the grinding amount is the part close to the outlet of the bevel.
[0043] Further, based on the simulation optimization supercharger turbine model, a model tangent line is determined,
[0044] Based on the model tangent line, a simulation model cutting is carried out, an optimized design three-dimensional drawing is obtained according to the cut simulation model, and a blank casting of the optimized supercharger turbine is carried out based on the optimized design three-dimensional drawing.
[0045] The utility model also provides a supercharger turbine, which is made by the method for optimizing the inherent frequency of the supercharger turbine.
[0046] Please refer to Figure 4 , Figure 5 and Figure 6 Understandably, the booster turbine 100 of the utility model is a post-treatment booster turbine, comprising a back 10, a center hub 20, second blades 30 and a rotor shaft, the center hub 20 is arranged on one side of the back 10, the rotor shaft, the back 10 and the center hub 20 are coaxially arranged and fixedly connected, the second blades 30 are arranged between the center hub 20 and the back 10, a turbine airflow channel 40 is formed between the center hub 20, the back 10 and two adjacent second blades 30, the turbine airflow channel 40 has a radial air inlet arranged close to the back 10 and an axial air outlet arranged close to the first trailing edge 501 of the second blade 30, the second trailing edge line 31 of the second blade 30 has an angle β with a radial plane, and the value of β is in the range of 10° to 11°.
[0047] Further, the eleven groups of second blades 30 are uniformly and circumferentially arranged.
[0048] Further, the second trailing edge line 31 (i.e. the chamfered line) has a trailing edge starting point 311 (i.e. a chamfer starting point) and a trailing edge ending point 312 (i.e. a chamfer ending point), the trailing edge starting point 311 is at the maximum diameter sharp position of the second trailing edge profile line, and the trailing edge ending point 312 is at the blade root chamfer 313 position of the second blade 30.
[0049] Further, the back 10 is a star-shaped disc back structure, and the second blades 30 are arranged on the outer convex lugs of the back 10.
[0050] Further, the value of β is 10.8°.
[0051] Further, the thickness of the second blade 30 gradually increases in the direction of the second blade 30 pointing to the center axis along the radial direction. The maximum thickness of the radial outer edge of the second blade 30 is 0.6 mm.
[0052] Further, the blade root chamfer 313 radius gradually decreases in the direction from the radial air inlet to the axial air outlet. The inlet blade root chamfer 313 radius of the second blade 30 is 1.8 mm, the outlet blade root chamfer 313 radius of the second blade 30 is 1.2 mm, and the blade root chamfer 313 is a variable chamfer design.
[0053] Further, the effective blade height of the second blade 30 is 9.8 mm.
[0054] Further, the rotor shaft is inserted into the center hub 20 and is in interference fit with the center hub 20.
[0055] Specifically, the wheel back 10 is a star-shaped disc back structure. The center hub 20, the wheel back 10 and one end of the rotor shaft are connected by electron beam welding. The other end of the rotor shaft passes through the compressor impeller shaft hole and the impeller is fitted into the groove on the turbine shaft with an interference fit. The impeller is fixed by a lock nut and the impeller is prevented from moving on the turbine shaft.
[0056] The turbocharger turbine provided by this invention features a design improvement based on the blade structure. This improvement increases the natural frequency of the turbine blades, ensuring that the natural frequency avoids the frequency of the excitation force. This prevents resonance in the turbine blades, reduces the occurrence of turbine blade failures, and solves the problem that existing technologies primarily focus on improving the vibration resistance of turbine blades from the perspective of the excitation source, resulting in complex techniques and high improvement costs.
[0057] Please refer to this again. Figure 7 The simulation method was used for experimental verification, including the following steps: Step S1, extracting the three-dimensional simulation model of the turbine; Step S2, meshing the turbine rotor; Step S3, solving the FEA of the turbine rotor; Step S4, high-cycle fatigue experimental verification.
[0058] The structural strength and vibration verification analysis of the pre-optimized turbocharger turbine were performed using simulation methods. Specifically, the steps included: Step S11, extracting the three-dimensional simulation model of the pre-optimized turbine; Step S12, generating high-quality second-order tetrahedral mesh elements using Hypermesh preprocessing software; Step S13, setting material parameters, loads, and constraints to perform FEA analysis and extracting the FEA results, where the first-order natural frequency was 11945Hz; Step S14, conducting high-cycle fatigue tests on the pre-optimized turbocharger turbine, with three turbines running for 100 hours each, resulting in turbine outlet blade tip drop failure.
[0059] The structural strength and vibration verification analysis of the optimized turbocharger turbine were performed using simulation methods. Specifically, the steps included: Step S21, extracting the three-dimensional simulation model of the optimized turbine; Step S22, generating high-quality second-order tetrahedral mesh elements using Hypermesh preprocessing software; Step S23, setting material parameters, loads, and constraints to perform FEA analysis and extracting the FEA results, where the first-order natural frequency was 13061Hz; Step S24, conducting high-cycle fatigue tests on the optimized turbocharger turbine, with three turbines running for 100 hours each, resulting in turbine outlet blade tip drop failure.
[0060] The optimized turbocharger turbine provided by this utility model has a natural frequency that is 10.18% higher than that before optimization. The turbine exhibits superior performance in terms of mechanical stress and vibration frequency under the influence of centrifugal force, temperature, and aerodynamic loads. It can improve the natural frequency of turbine vibration, enhance the turbine's vibration resistance, and avoid the risk of high-cycle fatigue fracture. It can also improve the overall reliability of the turbocharger.
[0061] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A turbocharger turbine, characterized in that, The device includes a wheel back, a central hub, second blades, and a rotor shaft. The central hub is located on one side of the wheel back. The rotor shaft, the wheel back, and the central hub are coaxially arranged and fixedly connected. The second blades are located between the central hub and the wheel back. A turbine airflow channel is formed between the central hub, the wheel back, and two adjacent second blades. The turbine airflow channel has a radial air inlet located near the wheel back and an axial air outlet located near the first trailing edge of the second blade. The angle between the second trailing edge line of the second blade and the radial plane is β, and the value of β ranges from 10° to 11°.
2. The turbocharger turbine according to claim 1, characterized in that, The second blades of the eleventh group are evenly spaced along the circumference.
3. The turbocharger turbine according to claim 1, characterized in that, The wheel back has a star-shaped disc back structure, and the second blade is arranged on the outer convex lug of the wheel back.
4. The turbocharger turbine according to claim 1, characterized in that, The value of β is 10.8°.
5. The turbocharger turbine according to claim 1, characterized in that, The thickness of the second blade gradually increases in the radial direction pointing towards the central axis.
6. The turbocharger turbine according to claim 1, characterized in that, The blade root chamfer radius is set to gradually decrease along the direction from the radial air inlet to the axial air outlet.
7. The turbocharger turbine according to claim 1, characterized in that, The rotor shaft is interpolated into the central hub and is interference-fitted with the central hub.
8. The turbocharger turbine according to claim 1, characterized in that, The effective leaf height of the second leaf is 9.8 mm.